I can advise you based on personal experience:
It is only a matter of time before the board will conk out. Bulging caps and one split means its days are numbered - very numbered - possibly in the single digits.
One day your system will likely hang or BSOD or reboot itself where it will hang on bootup. Then it will turn on, but you won't even get video.
The chances of it taking out anything else is very slim.
However!!!!!! If you want to put your HD into something else and simply boot from it, you are in for a variety of surprises. First and foremost, the hardware settings stored in your system properties will be different than those of the new board. So when you try booting, you will very likely get part way into the deal and have it BSOD on you. Then the only option is to re-install windows. You can boot from the Windows CD and try the repair console. You may or may not succeed. The next option here is to redo your hard drive and re-install everything.
One however to that one is if you find a mobo with the IDENTICAL chipset. Then you may be able to boot it up and have it do the hardware shuffle without crashing. The only chipset I have had any success at doing this with without too many problems is VIA
Getting some replacement caps may work but you have to be VERY careful. See my thread that I have going just a few down from the top on Motherboard Repair. Last night I pulled a couple good caps from an old board and soldered them into my dead board. I was very careful and did the job right. I have more than 2 caps burst so I replaced the 2 worst looking ones. Result? Mobo still dead. If I can find a couple more of the correct value I am going to try again. Chances of fixing it are slim, but I am one who will try my best to fix it.
Best advice I can give you is to find a replacement board SOON! Real soon.
Now listen close to this one;
Next best advice that goes with that, IF you don't want to redo your hard drive is to go into the system properties / Device manager and DELETE EVERYTHING!!! Remove all drivers, especially the chipset drivers. Do the mouse and keyboard last. Remove absolutely everything. When it prompts you to reboot, select NO. Once you have deleted all drivers, hardware, motherboard resources etc., shut the computer off and DO NOT start it back up. Install your new motherboard and ONLY THEN start it back up. WIndows will now detect all your hardware based on the new board and you will have to install all drivers etc. for you hardware.
Doing it this way, your programs should all still work and you should not have to redo the HD. If you wait until it dies, then the previous description of redoing everything will likely apply.
BUT, if you want to redo the HD, then just let it run until it croaks. Just MAKE SURE you have everything backed up.
I have had 3 or 4 boards go out on me in the past few years. With 8 computers running 24/7 in my house, I get my share of hardware issues, including blown caps. They give little warning - usually the only warning is unexpected hardware issues like USB not working of sudden self-reboots and things like that.
Once the caps blow, it is likely that something else will go in the board due to wrong voltages and such.
Just know that you have very little time left and your board is toast.
And last but not least, run it only when you use it. Shut it off between uses.