Cell phones can be a very fickle business, since their innovation and development can be rapidly accelerated due to new announcements from competitors. The original Sony Ericsson XPERIA X1 was made by HTC and powered by Windows Mobile, but that changed with the more recent release of the XPERIA X10. That phone gets Google Android.

Perhaps the XPERIA X10 is still too big for your tastes or you’d prefer to have a hardware QWERTY keyboard too? That’s where the newer Sony Ericsson XPERIA X10 Mini Pro. Announced in February and set for release in Q2 2010, the XPERIA X10 Mini Pro is the smaller cousin of the X10, but it still boasts much the same kind of functionality, including the Android operating system. You’ll also notice the slide-out QWERTY keyboard, which is smaller than the one on the X1.

In terms of other features, the smaller 2.55-inch touchscreen display features just a 240 x 320 (QVGA) resolution. It also has a scratch-resistant surface, accelerometer, Timescape user interface, microSD expansion, 3G connectivity, 802.11b/g Wi-Fi, 5-megapixel camera, geotagging, and a Qualcommo MSM7227 600MHz processor.

Nothing has been confirmed at this point, but the rumor is that Rogers Wireless in Canada could start selling the Sony Ericsson XPERIA X10 Mini Pro smartphone this June. If you don’t want the keyboard and opt for a thinner profile, the XPERIA X10 Mini may also be sold at the same time. Rumor points toward $50 for the X10 Mini and $70 for the X10 Mini Pro with a new qualifying contract.