What files do you need to change to change the algo?
I myself am a large holder of devcoin and the ability to mine with another algo would probably bring more network hashpower as well as more coin popularity.
It depends which algo.. im not sure how much work it is. If its as simple as changing the getwork routines im all for it, but if it means changing the way blocks are stored on disk or memory then i disagree. The mining part is seperated pretty well now in the new base..
Remember that since the hash is so high it may not make economic sense to try to mine with another algo? How will you find a block when competing against asics? Not sure how multi algo works in this regard.
Also think about the fact that miners only get 10% of each block.. is it really a miners coin? Maybr when value is realy high.. but the security is important and if the merge mined pools arent helping thrn we can investigate other algos to improve security.
You'd essentially need a version scheme. E.G. SHA256 has a block version number of 2. and Scrypt has 3, etc etc.
Each Algorithm Would have its own difficulty and so that means theres no competition between asics.