Update: This update is rolling out now, and is expected to hit all customers within four days.
If a leaked internal document obtained by SprintFeed is to be believed, then owners of the OG Galaxy Tab on Sprint should finally join the Gingerbread club on July 5th. This update will also bring added support for HD Bluetooth to the seven-inch tablet, on top of the added benefits and goodies of Gingerbread.
This timeline seems to be about right, as Samsung just released the source code for the Galaxy Tab SPH-P100 Gingerbread kernel. This means that, aside from receiving a much-needed bump up to Gingerbread, you should also see some custom kernel action popup shortly after.
You can grab the source code by heading over to the Samsung Open Source Developers Center and downloading the file labeled "SPH-P100_OpenSouce_GB_Update.zip."