If you are running SQL Server 2008 and haven't yet installed the SP1 CTP, you may want to check out Cumulative Update 4 (build 1798) in KB #963036. You obviously won't be able to install the hotfix if you already have the SP1 CTP, even though the new cumulative update contains some fixes that aren't in SP1 (and won't be when it is released).
When I initially downloaded these files, they were about 200K and, just as rumknight commented, had this error message when trying to extract:
I sent a note on to Microsoft right away, and while I have not received a response, in the meantime I tried to download using Google Chrome, and it seems to be getting the correct files this time (don't laugh at my slow download speed, I am doing this inside a VM whose host is connected to a slow work VPN):
So I'm not sure if they've fixed the downloads and IE is still stuck on a cached version of the files, or if Chrome really is better at handling downloads, but it might be worth trying if you are still getting the incorrect files in IE.