Apple just dropped a bomb whilst Eric Schmidt was giving his MWC Keynote.
They've also put an interesting message on the invitation:
We have something you really have to see. And touch.
I believe by saying there is something we have to see I think Apple are teasing the fact it has a high resolution screen. Also, some comments on The Verge article are suggesting there is no Home button. Whilst others say it’s probably in landscape mode I think this might be what Apple are hinting at by mentioning touch. It’s possible to use the iPad today without touching the Home button at all due to the multi-touch gestures they introduced with iOS 5.