Updated from March 10 to include analyst comments in the sixth paragraph.

In an unusual move, Apple (AAPL) is slated to hold an event today showing off a new iPhone, an introduction usually reserved for September.

Given that the new iPhone is not expected to be a major upgrade, it may not provide the fanfare it normally would, and so Apple is likely to have a few more aces up its sleeve. Also expected to make their debuts are new versions of the iPad and possibly an upgraded Apple Watch.

Here's what to expect from the big event, which saw invites gather the usual amount of attention from the press and analysts.

iPhone SE

Apple is expected to unveil a new version of the iPhone, known as the iPhone SE, a name which was first reported by 9to5Mac's Mark Gurman.

Essentially an updated version of the iPhone 5s, the iPhone SE will come with a 4-inch screen and is expected to take the place of the iPhone 5s in Apple's iPhone lineup, which would leave it with the iPhone SE, iPhone 6 and 6 Plus and 6S and 6S Plus.

"We do not expect the new hardware or software to materially alter our outlook for earnings or our view of the stock," Pacific Crest analyst Andy Hargreaves wrote in a note to clients last week.

In addition to having a 4-inch screen, the new phone will come with the A9 and M9 chips, which were first introduced as part of the iPhone 6s and 6s Plus last year, at an event which TheStreet attended. The new phone will also come with other features already available on newer iPhone models, including always-on Hey Siri support, Live Photos, an upgraded 8-megapixel camera, as well as Apple Pay.

Jackdaw Research analyst Jan Dawson expects the new iPhone to help move the needle on Apple's sales.

Apple is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio.

Exclusive Look Inside:
You see Jim Cramer on TV. Now, see where he invests his money and why Apple is a core holding of his multi-million dollar portfolio.

Want to be alerted before Jim Cramer buys or sells AAPL? Learn more now.

Dawson said it all depends on how the new iPhone is positioned.

"A few years back, there was a lot of chatter ahead of time about the iPhone 5C, and yet that ended up being a lot less disruptive than a lot of people imagined," Dawson said via email. "I suspect this new iPhone will end up being a subtle rather than radical departure from Apple's recent pattern, with a design more in keeping with newer iPhones but specs that are somewhat less powerful."

Pricing is unknown at this point, but KGI Securities analyst Ming-Chi Kuo expects the new iPhone to be priced between $400 and $500. By comparison, an unlocked iPhone 5s costs $450 and an unlocked iPhone 6 starts at $649, so this potential pricing strategy makes sense.

In the most recent quarter, Apple sold 74.8 million iPhones, below Wall Street estimates and up just 0.2% year over year.

Apple shares have taken a hit in recent months, as concerns about stagnating iPhone sales have crept up, with investors wondering whether Apple's market share has peaked. As of the end of the fourth quarter, Apple had 18.7% of the smartphone market, down from 19.7% in the fourth quarter of 2014, according to research firm IDC. IDC noted smartphone makers Huawei, Lenovo (LNVGY) and Xiaomi all increased their market share year over year.

A turnaround isn't expected this quarter, with Apple CEO Timothy D. Cook saying he thinks iPhone sales will decline in the upcoming quarter, which would be a first.

Interestingly enough, both Cook and CFO Luca Maestri were confident in their remarks on the fiscal first-quarter earnings call that Apple's second quarter, which runs from January to March, would be the toughest year-over-year comparison for a number of reasons, perhaps hinting at the event. 

iPad Pro mini

Apple is also set to show off a smaller version of the iPad Pro, a tablet aimed at the enterprise market.

At the March 21 event, whose date was first reported by Buzzfeed's John Paczkowski, Apple is expected to show off a 9.7-inch iPad Pro, a size that had been reserved for the iPad Air.

Apple is expected to aim the tablet more toward enterprise buyers and less toward consumers. It will be interesting to see if the iPad mini, a tablet geared solely towards consumers, sticks around, Dawson said. If it does, it will be interesting to watch how Apple re-positions the iPad line.

The iPad Pro mini is expected to include a 12-megapixel back camera, as opposed to the 8-megapixel camera that came with the original iPad Pro. It's also likely to have the ability to record 4K video, and come with a A9x processor, as well as support for the Apple Pencil and a new Smart Keyboard (shown above), suited for the smaller screen size.

A smaller iPad Pro could also help juice tablet sales, which have fallen sharply in recent quarters.

In the fiscal first quarter, Apple shipped 16.1 million iPads, down 25% year over year, making it several quarters in a row in which iPad shipments have declined.

Apple Watch

Apple may not show off a new version of the Apple Watch, which was officially unveiled last March, but Apple certainly has some news to share about the smartwatch.

According to 9to5Mac, Apple will focus on new bands for the Apple Watch, as well as new software. Expected are an expansion of the Hermès partnership, as well as new colors for its rubber bands.

Agency MBLM recently put out a survey asking Apple Watch users what new features they would like to see. The top answers included the removal of tethering to the iPhone, as well as making the Watch easier to use.

Still, IDC reported that the Apple was the second-best-selling wearable vendor during the fourth quarter, selling around 4.1 million Apple Watches, behind only Fitbit (FIT) . For the full year, IDC reported Apple shipped 11.6 million Apple Watches, behind Fitbit and Xiaomi.

Apple does not disclose Apple Watch sales figures. It includes the Watch in its Other Products segment for its sales numbers. In the fiscal first quarter, Apple said revenue from this segment rose 62% year over year and 43% sequentially to $4.35 billion.