I D/L the new version upgrade on my droid X version.2.3.15.MB810 and it deleted my droid market app, its werid so how can I get that app again ??
According to other users with this same issue the only way to get it back it to do a factory reset. Back up any data you want saved and factory reset your phone, this will bring it back to a "brand new, out of the box state" The 2.2 up date will remain so dont worry about having to reload that.
This will solve your issues and many more you dont know you have yet after the 2.2 upgrade
There is only 2 ways I know that seem to work.
1. Reinstall app from a market backup apk (EStrong File Explorer works well)
2. Hard Reset on device
If you decide to do a hard reset, check out this area,,, http://community.vzw.com/t5/DROID-X-by-Motorola/Minimize-Droid-X-Issues-After-Froyo-Update/m-p/29658...