It is still slightly profitable to mine LTC and it is definitely profitable to mine alts.  Its just a grind figuring out which ones to mine and when to sell what you get.  I know that I looked at LTC about 8 months ago and passed on mining because it wasnt profitable enough (I was looking at $800 in yearly profits from my crap NVIDIA card).  But then the price shot up, and I was very very wrong about it not being profitable.  If you have faith the price will rise again, then yes, its profitable.

Yeah primecoin is the way to go with the CPU.  Dont even waste the cycles on a scrypt coin unless your jumping on a brand new coin, and even then, the window for it to be effective is very short.  Get in one of the primecoin pools and go from there.