This looks like the overheating issue with launch Wiis. turning WiiConnect24 off (red power light) should hopefully prevent this as the ARM processor in the GPU will have less work.
If nintendo need to send a replacement your shop account will be reassigned to the new serial number so you can redownload VC games and WiiWare. Save data should normaly be transfared but might be lost if your unluckly.
In the UK out of warranty repairs cost £29.00 for minor repairs or £68.50 for physical damage and will be returned within 7 days.
In Europe we've been able to to buy wii points cards with club Nintendo stars since December 07
400 stars to 100 points, stars per game depends on price (<£26 = 100, £26-43 = 200 >£43 = 250)