I felt Kasavin was the best there was in the business, once he left Gamespot the site went into a decline from there. The Gerstmann debacle was what sealed the deal. I'll still go there to check out old reviews of games but as for new material, I stay clear of Gamespot.
I dunno about leave for good, I'll probably adopt giantbomb as my main source of gaming information, depending on how the forum turns out, but ever since the Gerstmann affair I've liked GS less and less...especially because of all the new editors. And Kevin Van 'Ord. He seems like a nice guy but something about him makes me...not like him (its not the gay thing, its more the credability of his reviews).
other than E3 i have barely visited Gamespot since Jeff and co left. With the exception of Aaron and KVO and Thor, there just isn't any personalities/characters there any more. Any site can do videogame content but what made gamespot great was the stuff were so awesome and had a great dynamic that they were so entertaining. i mean compare the hotspot to the bombcast . both report on pretty much the same stuff but the hotspot is a snooze fest and the GBC is just fun to listen to.
It will probably depend on how active the giant bomb forums will become in time, right now I pretty much only use gamespot forums to ask for help with games, and i always get an answer within 5 minutes, so its very convinient that way. Other than that the gamespot forums is a complete clusterf*ck