We had a similar problem. (Red light/blue light flash on button press.) Ours was a completely unmodded Wii. We had left it plugged in but unused for an extended period. What we ended up doing was an extended reboot. Unplug the power adapter from the Wii *and* the wall and let it sit for about 10 minutes. Then re-assemble the system and try starting it again. If, when you were trying to fix it, you didn't wait a long time then the console won't reset completely.
Found this similar description of the fix (there are a lot of ads, you'll have to go past some to see the process):
http://hubpages.com/hub/My-wii-wont-turn-on-Why-my-wii-wont-power-on
I figure the original poster is long since fixed, but this description sounds like something that comes up for a lot of people.