Depends on what you mean by realtime. In most cases (stats-wise, anyway) analyzing a non-stored infinite-length data stream is a very different challenge from analyzing a stored, finite-length data set.

Streaming algorithms do exist for many basic statistical measures. But in many other cases, the best streaming algos aren't cheap or accurate enough to be useful.

Bucketing can sometimes substitute for a bona fide streaming algorithm. But again, there's plenty of cases where bucketing won't work well enough to make it useful.

I haven't really looked at Statwing yet--the premise is really tantalizing, though. Gotta find an excuse to throw a spreadsheet in there and see what comes back.

+1. I really like the intuitive interface and the speed with which I can conduct analysis. It would be great to have a library of feeds for each user that is automatically curated / updated. This library could include both public datasets (fore free) but also proprietary feeds specific to my industry or even my company that are only accessible by me (which I would pay for).