Good question - the copy is approx. 10gb total with about 10,500 files. The number of files could very well be the underlying issue, as a network test utility on this server can read/write a single 10gb file in about 75s.
So perhaps the copy is running as fast as possible with regards to the hardware and NIC config. A secondary question would then be, is this as fast as a Windows 2008 copy can be with this many files? Is it simply the number of files that is causing the slowdown? Interesting (sort of)