I say “killer” only because if Google gets in, it’s going to be good. BigTable, an internal Google database product that they use to support their fast read/writes on petabytes of data (yes, peta-), is going to be released as a consumer offering in the same mode as Amazon’s SimpleDB. See the TechCrunch writeup here.
Good news for web startups? Certainly. Good news for Amazon? Probably, only insofar as a new industry – cloud computing – will support lots of competitors, and Google getting in only further validates the concept (as if it needed validating to begin with).
If Google can make it as easy to use as their other consumer offerings, like Maps, then we’re all in for a treat.