First of all: affect. Not effect. This really bugs me a lot, lately.
But yeah, well I don't know. I bet he's still active, he supposedly posted that message that he's not Dorian Nakamoto. I guess it won't do much to the price, though...
Irregardless, I think the general bitcoin community could care less about Satoshi anymore. So, he shows up - is that really going to make some big-traders change there positions and cause that large a Bitcoin price swing?
On a more serious note, most Satoshi news is probably going to be bad for the price. Right now people are trying to forget that one person may literally own a million coins (give or take a bunch) - if Satoshi comes back into existence and there is even a shred of evidence he may sell some of the coins, expect madness.
Of course, I don't expect Satoshi to let that happen. I personally suspect that he has already sold a fairly large number of coins in order to support himself and profit over the years. We just don't know those addresses, because we all have this extremely defined picture of what a "Satoshi wallet"
must look like. Ever consider that he may have just plopped a nice amount of coins in a couple wallets (instead of just leaving 1 block in each wallet), like most users?