By even considering deferring your Mario Galaxy purchase, you've moved way down on my "cool" list, ShyGuy

But seriously, your reasoning is sound enough, and financial planning is always important. Next year make it a point to invest in an ETF, though*.
So here's my priority list - Strikers and Corruption were previously on it, but I've gotten them both now.
Definites1. Super Mario Galaxy - November 12
2. Super Smash Bros Brawl - December 3
3. (TIE) Resident Evil: Umbrella Chronicles - October / Ghost Squad - November 6 (will pick up best one, will rent other)
4. NiGHTS - November 13
5. Zack and Wiki - Fall 2007
6. BWii - October 29
7. FIFA 08
Honourable Mentions- Dewy's Adventure - September 4 (probably missed the boat on this one)
- Soul Calibur Legends - November 6 (it's looking better but still unsure)
- Smackdown vs Raw 2008 (why not continue Day of Reckoning, THQ? Why??)
- Medal of Honour (token ShyGuy mention, but hurts badly that it comes out with SMG)
Not interested in personally, but deserve consideration- DDR: Hottest Party (non-spinoff DDR game on a Nintendo console!)
- Guitar Hero III (first Guitar Hero game on a Nintendo console!)
- Dragon Ball Z 3 (online)
- Rayman Raving Rabbids 2 (hopefully fleshed out)
- Godzilla (token Arbok mention)
Unknown whether will come out in 2007Trauma Centre (would be in my Top

Dragon Quest Swords (probably won't pick this up, maybe a rental)
* The usual disclaimers
EDIT: I just realised that NiGHTS comes out right next to Galaxy, too. I may have to put that off to next year.