i don't place too much stock in the belief that it's coming any time soon due to the update of Fring. here's my thinking:
Fring is available for more than just the Evo, so the developers are covering devices ahead of time. this isn't to say the Evo won't get Gingerbread, just nothing to take note of due to this update.
Alot of developers are probably updating their compatibility for their apps--which will be available to devices that won't get Gingerbread. (ie FakeApp could be upgraded compatibility but available to the SamsungMoment and the Evo---but this doesn't mean that the Samsung Moment, still running Eclair 2.1, is getting updated to Gingerbread just because it received an application update)
If it were something that was a Stock app/bloatware (ie QIK) then i'd be more inclined to believe Sprint told the developers to ready their software for the upcoming Gingerbread push. (and by upcoming, i mean within the year)
and yet....i still hold hope..ha