I haven't played with Google Docs for a while, but news of a form designer to ease spreadsheet input intrigued me. A lot of spreadsheets, especially in an office environment, are actually pseudo-databases. So why not treat spreadsheet data entry like a database?
It's a great idea, but the initial execution is a bit disappointing. The form designer is pretty limited: some nice Ajax-y touches, but a restricted number of field types, and no easy way to enter dates (pre-population? popup calendar?). I have a couple of work-related spreadsheets which I update on a rolling basis, and which I'd happily move over to this kind of form-based approach... but sorry, not yet. Wufoo still seems to be the leader in online forms... and with the addition of payment processing, it opens up all sorts of possibilities.
But the whole Google Docs experience is definitely improving. I tried using the Prism browser, which is basically Firefox stripped bare: and it made for a more natural 'Office-y' experience. It was actually surprising how much the lack of familiar browser screen furniture helped. But I think it really needs to be offline-enabled (via Google Gears or Firefox v3?) to make its breakthrough. That may not be far away, as it happens: offline Google Docs access has been spotted in testing.
I've been using these a lot lately, they're definitely improving all the time. Been hearing about the offline synching for a while from a friend, they are impressed. Biggest annoyance for me is the lack of export function for the slideshow, that is way behind docs and sheets in its development.