James, I hope you'll consider the negative impact this could have on Allan's perception in the community. Most will find it at least partially humorous, but others (see some of the comments below) won't recognize that it's not actually Allan making the joke.
With all the discomfort present in the TM community associated with the long wait for TM2, there will be a fair number of people who will come to believe that Allan used April 1st as an opportunity to give his user base the finger. They'll carry this feeling forward, never realizing that this was a spoof.
I'm planning on changing the page after today, letting everyone know that it was a hoax and giving some information on my favorite TM plugins to bridge the gap between TM1 and TM2.
I have considered changing it to something that's more obviously a joke, since it's been caught up in the twitternets, but for the most part the response I've seen is positive.
I have mad respect for Allan, but he has been the butt of a lot of running jokes "Vaporware of the Year" awards and such. Ultimately, I don't think a lot of people will be taking things too seriously today and hope it doesn't reflect negatively on Allan, but if it does end up as a bit of a kick in the butt, he could use it. I would hate to see his awesome tool fade into obscurity.
http://blog.macromates.com/
There's an extra 'c' in the submitter's URL.