That poster is indeed the one of the latest iPad event.
I think the 1st of March is quite plausible. I think they might even have had today as initial release date, but due to processor problems they postponed it two weeks.
Now why would I think that? Well, it's quite a simple puzzle: As on any event, it doesn't all fit around just one product. I assume the 'free' subscription to The Daily ending februari 14th, might have indicated an iOS release on the 15th, and thus an event on the 15th. Possibly an event where MBP would be released as well as a device for 4.3 (New iPad, possibly?).
Now I have read some news earlier on several sites suggesting the Intel problem would have only delayed Apple 2 weeks. This adds up to the postponed iOS release / prolonged free Daily subscription.
I think that due to processor delivery problems, they have postponed the event by two weeks to March 1st, clarifying the longer free subscription to the daily to Februari 28th.
I think the event will not only be about the MBP, but will somehow include iOS 4.3, and why build an event around an iOS release when not releasing a new iOS product? Or announcing one? I think: Say hello to the new MPB and iPad 2, while we all upgrade our current iOS devices to 4.3 on March 1st!