Despite being under the kosh, financially speaking, Sony Ericsson were out in force at last weeks Mobile World Congress, showing off four new models along with one Old favourite. The recently unveiled Xperia X10 Mini, X10 Mini Pro, Vivaz and Vivaz Pro sit alongside Sony Ericsson’s next big (and we mean that in every sense of the word) launch; the Xperia X10. On to that in a moment but first the new additions.

The Vivaz Pro is almost a carbon copy of the standard version (which we’ve managed to take a look at previously) save for two notable differences; the inclusion of a full slide out QWERTY keyboard and downgrading the camera from 8 to 5 Megapixels. HD video capture is still present though along with the added extras such as continuous autofocus and easy uploads to your favourite sharing sites such as YouTube. The addition of a QWERTY keyboard to a Symbian touchscreen device puts the Vivaz Pro in direct competition with the Nokia N97 Mini but the extra multimedia capabilities should edge the Sony Ericsson phone ever so slightly ahead.

The design of the phone is nice with a good in-hand feel thanks to Sony Ericsson’s new Human Curvature ethos (curves to match the human form). Better still, the slide mechanism feels reassuringly robust whilst the keyboard itself is comprised of good sized keys that offer good feedback. On to the software and for better or worse, the Vivaz Pro follows its QWERTY-less sibling in running Symbian. Sony Ericsson have made navigation to key areas of the phone more user friendly with the addition of tabs to the home screen, as seen first in the Satio. Let’s hope Sony Ericsson can avoid the software fiasco that blighted the Satio’s launch when the Vivaz and Vivaz Pro launch next month.

On to the first of three upcoming Android phones now and the Xperia X10 Mini. First things first, Sony Ericsson certainly aren’t kidding with that name, the X10 Mini is absolutely tiny and when held next to the full fat Xperia X10 looks even more so. Sony Ericsson are keen to promote the one handed usability of the X10 Mini and accordingly each corner of the touchscreen houses a customisable shortcut. Easy to set up (this does run Android remember), this makes navigation to key areas of the phone that much simpler. On to the subject of Android. The X10 Mini runs version 1.6 of Google’s OS and while you’re hardly going to be running SatNav on the diddy screen, the Sony Ericsson rep pointed out that the 2.55 inch display met Android’s minimum requirements and so should run pretty much all of the apps available in the Android Market app store.

With a range of colourful customisable covers, the one word that describes the X10 Mini is definitely cute. Sony Ericsson are clearly after the youth market with the Xperia X10 Mini and you wouldn’t bet against it being a huge success (once you’ve had a play and fallen for its charms of course). Our only complaint was the difficulty with messaging. Understandably, a 2.55 inch display is hardly big enough for a QWERTY keyboard so the X10 Mini makes do with an alpha numeric keyboard which does slow down text input. But before you text addicts moan, Sony Ericsson have an ace up their sleeve. If you’re only happy when your tweeting, pinging friends with instant messages or chatting on Facebook, Sony Ericsson has an X10 Mini for you; the X10 Mini Pro. It does exactly what its stable mate does but packs in a slide out QWERTY keyboard too! Perfect.

Now onto the device we’ve been waiting for for what seems like an eternity; the Xperia X10. Well, the device is slated for launch some time next month and from our briefest of hands on, Sony Ericsson definitely seem to be headed in the right direction. Concerns of unstable software and unresponsive menus can be put down to early samples because the device we played with was sharp enough to be the finished article. The 4.0 inch touchscreen not only looks great but is equally impressive to use and despite the full bodied design, the X10 never felt too big. The design itself is also a master stroke; this is a phone you’ll want to get out and show off. We won’t go into too much detail concerning specs because chances are you already know what the X10 is all about. All that we need now is for Sony Ericsson to actually launch the device to an increasingly impatient fan base. Click here to register for updates for the X10 and keep an eye on the blog and we’ll be sure to let you know as soon as it’s available to order.