Could the client not be shipped with the first x blocks good to go? Thought I read that somewhere…
You can download the blockchain seeded with 120,000 blocks. http://sourceforge.net/projects/bitcoin/files/Bitcoin/blockchain
One concern is the source of the block chain binary that you download (i.e., that one doesn't use SSL).
Also being discussed is how to implement a lightweight client that includes headers-only (i.e,. all data needn't be stored, just the headers)