I downloaded the maps on the leaked os2008, and it took me I guess about less than an hour to download All USA and Canada.

Maybe the servers are quite slow at this time as u know what happened when people were downloading the official *release* of OS2008, it was only 128MB and there servers were getting dam slow.

I would say wait for atleast a week or so and then try to download the maps again.

Hope that Helps.