Sony Ericsson launched three new handsets on the eve of Mobile World Congress in Barcelona in a bid to get in ahead of the wave of announcements expected at the show. Sony CEO Howard Stringer was on hand to show parental support for the joint venture, although partner Ericsson was absent from the presentations.

A new version of the Symbian-based Vivaz handset that Sony Ericsson announced inJanuary – the Vivaz pro – was on display, featuring a slide out QWERTY keyboard that the firm said added just 2mm to the thickness of the unit. But the focus seemed to be more on two additions to the Xperia range, the Android-based Xperia X10 mini and X10 mini pro, the latter, like the new Vivaz, sporting a sliding Qwerty keyboard.

With the two X10 handset, both about the size of a business card, Sony Ericsson is pushing all the technology down the range to the consumer, with the firm giving what in the handset manufacturing community have become the standard nods to social networking.

CEO Bert Nordberg conceded during his presentation that 2009 had been a “turbulent” year for the vendor. Sony Ericsson has given the impression of a company doing much soul searching of late, asearly promise has more recently given way to a lack of direction, visible in its product portfolio. The language being used at Sunday’s press conference certainly chimed with current trends among handset vendors and the firm revealed the areas in which it is looking to demonstrate leadership.

Chief Creation Officer – a demonstrative title if ever there was one – Rikko Sakaguchi of the firm’s desire to “make people smile” with its new handsets and made much of the products’ “human curvature” design features. Nordberg spoke about a “major new programme on quality” and pledged that the vendor would be producing the world’s greenest handsets by 2011.

But it was the presence of Sony CEO Howard Stringer that was the most interesting element of the press conference. He spoke of a “converged home environment” and made carefully non-committal noises about Sony’s research into the use of common operating systems across its range of consumer electronics products.

That Sony Ericsson wheeled out the big guns shows its commitment to re-establishing itself within the handset league tables. Ericsson’s exposure to its troublesome joint ventures has often been noted but its absence from the event could just have easily been explained by the greater relevance of Sony’s expertise and brand to the handset environment.

Either way Sony Ericsson has to prove itself to its shareholders. Never mind what feelings it wants to inspire in consumers; it has to make its parents smile now.