Application stores seem set to be one big trend, with Nokia, Microsoft and Samsung all expected to announce app stores, while BlackBerry-maker Research In Motion will be showing off its new store too.
We're also expecting a bunch of Android handsets to be announced this week, from various manufacturers - giving us a sense of what kind of impact Google's platform will make in 2009.
Location-based technology and social networking services are bound to cause a stir - sometimes rolled into one offering. And, of course, most of the big mobile games publishers are here, even if they haven't booked stands.
We'll be reporting and interviewing throughout the week, and you can bookmark our dedicated MWC09 page to keep up to date on our coverage.
As you'll see there, we're also micro-blogging from the show, so give us a follow on Twitter if you want to stay up to date with that.