Just got back from the testing center.
I studied about 2 months, hard core. Every free moment I spent reading. Weekdays: 1 our each way on the subway (to/from work), and 2-4 hours after work. Weekends: 8 hours Sat and 8 hours Sun.
Before taking the test I felt like I knew all of the technologies very well. I focused mostly on Advanced BGP, Advanced Multicast, QoS, OSPF, and EIGRP. Of course I also covered the other technologies on the blueprint. A lot of the studying was refresher from the CCNP, and diving deeper into technology.
The test itself was extremely disappointing. The questions were more ambiguous than ever, and did not test you on advanced concepts, or your understanding of how the technologies really work. The 4x CCNP tests that I've taken were A) Overall more difficult.

Focused on the technologies. Not bizarre/ambiguous gotchas.
Some of the diagrams I had were completely ineligible!! As in, you couldn't actually see the diagram or the command output because the resolution was totally jacked. Now ambiguous questions I can deal with, but diagrams that I cannot read because they've been shrinked 10x and have some totally messed up resolution is not acceptable.
study materials:
CCIE R&S certification Guide
Bits and pieces of Routing TCP/IP Vol I & II
Bits and pieces of my old CCNP books
A whole lot of RFCs
Other peoples blog posts on various protocols & technologies
Dynamips & some real gear
I'm looking forward to the lab!