hardware is a lot more powerful and cheaper today than it was a few years ago so you can consolidate a lot more databases on one machine. MS is going to sell a lot less server licenses of R2 than previous versions.
few years ago our first x64 servers cost $30,000 to $40,000 each for dual quad core, 32GB of RAM and a few other features. this week i was emailed a quote for a Proliant G6 with dual hexacore, 72GB of RAM, 5 year 4hr response time support, advanced ilo and other extra monitoring features for $15000 a server. HP says that you can get a 20 to 1 consolidation ratio of Proliant G4 and earlier hardware going to Proliant G6. even at 10 to 1 it's a huge $$$ savings