The Mobile World Congress is the biggest wireless trade show of the year, with 50,000 attendees and 1,300 exhibitors. The fun begun on Sunday night in Barcelona, Spain. So what will happen this year in Barcelona? As usual, we expect quite a bit, including the long-rumored PlayStation phone, a few tablets, and more Samsung Galaxy S devices. Read on for the full scoop on what's (probably) to come. Sony Ericsson We've known it was coming for a long time, but next week Sony Ericsson's PlayStation phone should really happen. Over the past few months we've caught occasional glimpses of the Xperia Play, but it wasn't until a Super Bowl commercial that Sony Ericsson officially acknowledged that the phone exists. Sony Ericsson also should reveal the Xperia Neo, which was caught on camera earlier this week. LG LG will host a conference the next day as MWC officially opens. The company has been pretty open about its plan to show a new 3G version of its Optimus smartphone. At this point, we're not sure how we feel about the basic concept of a 3D handset, but we'll offer our opinion once LG shows it off. Nokia Nokia didn't announce new products at MWC 2010 and we expect that the company will also be short on new handsets this year. Yet, that doesn't mean that Nokia will be laying low. Instead, we're counting on the Finns to highlight a new smartphone strategy. Nokia CEO Stephen Elop will get a jump on MWC by holding an investor's conference on February 11 where he will unveil whatever strategy that will be. Though Nokia continues to sell more phones worldwide, a renewed focus on smartphones is sorely needed. Reuters reported this week that the company was halting development of its MeeGo platform. Plenty of opinions exist about what Nokia should do--Windows Phone 7 may be the likeliest option--and Elop recently championed the need for a new strategy in a somewhat scathing internal memo.