NEW YORK ( TheStreet) - It's bad enough that U.S. Blackberry ( BBRY) addicts have to wait another five to six weeks or so for a shiny, new Z10 touchscreen smartphone. Now, we're learning that the Q10 device (with the famous Blackberry QWERTY hardware keyboard) won't show up here until nearly summer. In an interview with the the Associated Press, Blackberry CEO Thorsten Heins told fans they'll have to be patient while U.S. carriers complete their testing of the new models before releasing them to the public. So, while the Z10 is available now in places like Blackberry's home base of Canada, as well as the UK, it's going to take another four-to-six weeks for American carriers to make sure it works properly on their networks. Applying that thought process to BlackBerry's second new device, Heins says the upcoming Q10, reportedly ready for worldwide consumption in April, won't be available at U.S. retailers until eight-to-ten weeks after the Z10 arrives - that's mid-May into early June. That could turn out to be a definite sales buzz killer for Blackberry. For the record, although we were told that our Z10 test unit was designed for use on AT&T's ( T) network (it does, LTE too) it seems to be T-Mobile friendly too. When we tried a T-Mobile SIM in our phone we were surprised to see the familiar fuchsia TMO splash screen. And the phone's network settings suggest that T-Mobile LTE connectivity could be an upcoming option. I'm not exactly sure how much testing is needed to confirm compatibility with U.S. carriers, but at least with our GSM handset the Z10 seems to work very well on both AT&T and T-Mobile frequencies. I'm guessing that the Verizon ( VZ) and Sprint ( S) CDMA versions have very similar settings too. Heins told interviewers that both the black and white versions of the Z10 are selling incredibly well so far. "It's beyond expectations. White is sold out already. The black is hard to stock up again," he said. "It's very encouraging. I won't share the number because I need to verify it, but we are getting a substantial number of users moving from other platforms to BlackBerry." "We expect the first global carriers to launch the BlackBerry Q10 in April," wrote a BlackBerry spokesman, in an email to TheStreet. "We will announce new pricing and availability information as carriers roll-out around the world. We are working closely with our carrier partners to accelerate their testing process, but cannot offer any specifics on US availability." --Written by Gary Krakow in New York. >To submit a news tip, send an email to: firstname.lastname@example.org.