Though it feels like we just left CES, the next gadget extravaganza is upon us. With 50,000 attendees and 1,300 exhibitors, Mobile World Congress is the biggest wireless trade show of the year. The fun begins Sunday night in Barcelona, Spain, and CNET will be there to bring you the latest news in handsets, operating systems, accessories, and applications.

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.

Whatever happens, Sony Ericsson will have a press conference this Sunday, February 13, at 9 a.m. PT. Check back then for what the company will officially unveil.

LG teases its upcoming 3D phone.

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.

Samsung Samsung also will hold a press conference on Sunday evening, and we already know that the next-gen Galaxy S is on deck for a full reveal.

The company has posted a teaser site and video on its Samsung Unpacked site, but of course, it doesn't say much about the smartphone. However, according to rumors, the device will feature a dual-core processor, 1GB RAM, and an 8-megapixel camera with 1,080p HD video recording. There's also talk of an NFC chip and Android 2.3.

Samsung could introduce a new Galaxty Tab in Barcelona.

It's also quite possible that we'll see the successor to the Samsung Galaxy Tab. Possible specs include a 7-inch, 2,048x1,200-pixel touch screen, Nvidia's Tegra 2 chipset, 64GB hard drive, and Android 2.3. In any case, Samsung usually goes all out for these events--last year, it had dancers and an aerial acrobat, among other things--so I'm sure we're in for a amusing good show.

HTC Unlike most companies, HTC is saving its press conference for Tuesday. In the past, the Taiwanese handset manufacturer has used the show to introduce a bevy of international phones, and we expect this year will be the same.

There is a rumor that the dual-core HTC Pyramid will land at T-Mobile, but as our Android Atlas blogger Scott Webster points out, it's likely that the company will save that announcement for CTIA 2011 in March.

Even if we don't see the Pyramid in Barcelona, MWC always gives us a good indication of what kinds of devices HTC will roll out throughout the year.

The big question is: Will HTC unveil a tablet

Microsoft It's hard to believe, but it was just a year ago that Microsoft took the wraps off Windows Phone 7 at MWC 2010. The company will be in Barcelona again this year and has a keynote address planned for Monday afternoon.

We expect it'll talk more about the upcoming software update, rather than new hardware, but you never know. If Nokia announces a switch to Windows Phone 7, then things will be a lot more interesting.

CNET's coverage begins Sunday and runs through the week. Be sure to check back for the latest updates and plenty of blogs, photos, and videos.