[tokuzumi]

When root was first available for the Sprint Hero, I rooted. When the 1.56 update came out, I loaded the stock Sprint 1.29 rom, and applied the 1.56 update (essentially un-rooting). Once I signed in with my google account, I went to the market and under "My Downloads", I could install all the apps I had installed prior to wiping my phone. You would need to save any data you entered into those apps. But at least your phone will know what apps were installed previously.