Early builds of system software leak more often than expected, and fortunately HTC Rezound owners can now rejoice. Not only had an Android 4.0 (Ice Cream Sandwich) kernel and system.img leaked a few days ago - but developers have already compiled a couple easily flashable ROMs for the public to try out. Not only that, they've taken out some of Verizon's 'bloatware' to help it run even smoother.
You'll have to try them both out to tell us which one you prefer, but they are very similar since they are based on the same leaked RUU 3.10.605.7. The first is RezROM by IIIboredIII and the other is CleanROM by scrosier. To install either, you follow the same steps as flashing any other ROM.
First, place the ROM on the SD Card. Reboot into ClockworkMod and wipe data and do a factory reset. After flashing the ROM, you'll be booted into fastboot automatically. From there just tap power and install the necessary kernel and boot.img. For now, all that seems to be broken are the animated data arrows - not bad at all for a couple days with the leaked source!