For one thing, your site isn't even SSL capable, so even if you are entirely honest, an attacker could alter the contents of the traffic between you and me, and I could end up downloading a different file than what you are hosting.   Each bitcoin blockchain binary from BitcoinCharts gets digitally signed so that the download can be verified as being truly the one built by the site.
 - http://eu1.bitcoincharts.com/blockchain/

Using your blockchain binaries means that I am trusting that you haven't injected data that would cause my client to think a transaction was valid, when elsewhere on the network that transaction will be rejected.

Using these is something unsafe, yet for small amounts the convenience might outweight the risk of loss.  Just wanted to make sure the risks of use got mentioned here.