You can't build an UTXO set (needed for validation) without doing most of the verification anyway (everything except signature checking, basically). If you mean trusting someone to build a pre-indexed blockchain for you, you're far better off running an SPV node - it's faster, needs less disk, needs less bandwidth to maintain, and doesn't require trust in a centralized source for your block data.

The current git head (pre-0. code still has some problems that cause initial syncup to be slow (in particular, the block fetching algorithm is crappy, and gets very easily confused to the point where it stops doing anything for several minutes). From reports, it also seems it's significantly slower at verifying on Windows systems. Still, if combined with parallel+optimized signature verification code (which may or may not make it into 0.8 release), and the block fetching system gets fixed, I hope we can get close to a sync time of 1 hour on reasonably recent systems.