Ooooh the irony! I have the same issue now

Spore started fine the first time, no problems launching it. I had the login issues everyone else is having, and then decided to just play offline. I proceeded to the settings as I always do first when I get a game, and set everything to max (like I did in the CC, my PC can handle it) and resolution to my monitors native: 1680x1050. Then I exited spore to allow the effect to take place.
I relaunched spore... nothing happened. The process is running in the background, but nothing came up. I waited a few minutes (first launch only took 20 sec or so).
I killed the process and relaunched spore; again nothing happened. I tried with spore in safe mode; nothing happened.
I rebooted and tried again (both with and without safe mode); nothing happened.
So I basically got it to launch once fine but now it wont.
I still have a few things to try so I'll keep you posted, feel free to add comments though.
UPDATE 1I just found this in the readme file: "It is not recommended that you run at fullscreen resolution if your monitor resolution has a height or width of 1600 or larger.", what the heck??
Could that be it?
UPDATE 2I tried using the switches -r:1024x768 and -w (first just resolution, then both) but it still doesn't launch, so it doesn SEEM like it's just the resolution that buggers it up.
UPDATE 3 (final)Ok I found the problem.
I went to the game folder then Sporebin and right-clicked on SporeApp.exe. Went to Properties, then the tab Compatibility and ticked the checkbox "Run this program as Administrator". It worked fine after that

I'm a bit puzzled though. There were no error messages to indicate it didn't have the right privileges, no pop ups, no nothing. And the first launch worked fine without it.
In any case, there's a solution if others are having the problem. Could the OP try it and see if it works for him?
If it does, then please change the title of the thread to include "(solution inside)".
-----Desktop PC Specs-----
Windows Vista Home Premium x64
Intel Core2 Quad Q6600 2.4 Ghz
4GB DDR2 800Mhz RAM
BFG GeForce 8800 GTX OC 768MB (Driver Version: 7.15.0011.7519)
2x400GB SATAII HDD