I've been waiting ages for this. Desktop, web-based, tablets, however.
Old timers may recall that Lotus Symphony had both database and spreadsheet features, like a multi-app. It was cool. At the time, Lotus Improv seemed like a healthy fusion, next logical step, minimum viable product.
Improv was victim of the Innovators Dilemma plus installed base inertia. I remain impressed that even with their market dominance, Lotus was experimenting, releasing crazy new products, and willing to eat their own children. (Though I can't forgive Lotus Notes, sorry.)
PG's original blurb (http://ycombinator.com/ideas.html):
"22. A web-based Excel/database hybrid. People often use Excel as a lightweight database. I suspect there's an opportunity to create the program such users wish existed, and that there are new things you could do if it were web-based. Like make it easier to get data into it, through forms or scraping.
Don't make it feel like a database. That frightens people. The question to ask is: how much can I let people do without defining structure? You want the database equivalent of a language that makes its easy to keep data in linked lists. (Which means you probably want to write it in one.)"
He's old enough that he should know better.