Although I'm not entirely educated in the workings of Bitcoin yet, I'd like to throw out there the possibility of each new version of the official Bitcoin client containing most of the block history, up to the point of release. Or would that be rather large?
Either way, I think we can all agree that something should happen to remove the inconvenience that comes with a currency like this.
From Satoshi -
We have the hashes for genesis block through block 74000 hardcoded (compiled) into bitcoin, so there's no reason why we shouldn't be able to automatically download a compressed zipfile of the block database from anywhere, unpack it, verify it, and start running.
The 74000 checkpoint is not enough to protect you, and does nothing if the download is already past 74000. -checkblocks does more, but is still easily defeated. You still must trust the supplier of the zipfile.
If there was a "verify it" step, that would take as long as the current normal initial download, in which it is the indexing, not the data download, that is the bottleneck.
Presumably at some point there will be a lightweight client that only downloads block headers, but there will still be hundreds of thousands of those...
80 bytes per header and no indexing work. Might take 1 minute.
uncompressed data using a protocol (bitcoin P2P) that wasn't designed for bulk data transfer.
The data is mostly hashes and keys and signatures that are uncompressible.
The speed of initial download is not a reflection of the bulk data transfer rate of the protocol. The gating factor is the indexing while it downloads.
As you can see, that idea has been considered, but discarded for above reasons.