What makes them interesting? In part its that they have a really dangerous batting lineup. The formerly retired Sanath Jayasuriya is an excellent batsman, and Australia's Adam Gilchrist is the only other wicket keeper-batsman in the same class as Kumar Sangakkara.
But what really makes them unique is their bowlers. They don't just have good bowlers, they have bowlers who are one-of-a-kind. There will never be another bowler like Muttiah Muralitharan - his deformed elbow makes him pretty much impossible to emulate. Now that Shane Warne has retired, he is undisputably the sport's premier wicket-taking spin bowler. Then there's the aforementioned Lasith Malinga. Not only does he have an unusual style of delivery, which has been much discussed, but now he's got hair to match. There's also Chaminda Vaas, who almost became a priest instead of a cricketer.
I can't predict that Sri Lanka will win the tournament, but I can say that they are the team to watch.