Seriously, and with Samsung's assertion that ALL of their Android-related software will remain open source unless Google themselves asks them to do otherwise, I see nothing to worry about. This device has Droid branding and is one of the first to carry VZW's LTE banner, so I'd expect pretty solid first-party support. Considering its basically a Galaxy S with S-AMOLED+ and an LTE baseband chip, I don't think it will be long before it can take advantage of the wealth of development the original Galaxy S saw, especially considering its likely going to be more popular than the original Fascinate ever was.
Even if not, though, I'd still be perfectly happy with it will all stock firmware. Samsung has stated that you can switch back to the stock Android launcher, and as always there's LauncherPro. Granted its still Froyo, but so is most everything else that's out or about to launch atm. Samsung has just developed the official Gingerbread update for the vanilla Galaxy S, so I expect we'll see it hitting the 2 GSM US carriers fairly soon. It will take time to adapt it for the CDMA versions, but I wouldn't expect it would be any more difficult for LTE. So my theory is we'll see Gingerbread for this the same time we see it on the Fascinate. If they don't bother updating the Fascinate further, I would still expect it on the Charge by the end of summer.