actually whole NT6 line was plagued with this, but for a reason
in short, all versions (SKU's) were installed on hard drive, all language packs, all components (SxS)
so user didn't had to use installation DVD for things...
but to surprise, i guarantee you that vista and win7 also fit on 700 MB CD with all updates
and also if you manually remove from Install WIM, stuff that you really don't need as "power user", you can also shrink install size to ~1.5 GB (this is case for x86, trust me i done it )