I am working on an SCCM deployment for the HP ElitePad as we speak. Testing this week.
The issue I am running into right now is, as soon as the OS starts "Setup Windows and Configuration Manager" I get a "Installation drive does not meet requirements" in the X:\Windows\TEMP\SMSTSLog\WindowsSetupLogs\setuperr.log. The generic task sequence error code is 0x80004005. A google search for that + elitepad yeilds an HP site saying "Install CU1 for SCCM 2012 SP1 on a Server 2012 OS". Excellent advice except I have CU2 installed. Dead end.
Anyway, to respond to your issue: I had the exact same error. I removed all the storage drivers from the WIN PE 4.0 Driver pack from the boot image and I got past this issue. I suspect that the newest drivers have issues so maybe I'll go back to the February 2013 set and try those (per the SCCM deployment PDF). I'm working off a hodge podge (one set from july 2013 if i recall correctly) of drivers and I get those errors and my error I described above - maybe they are all related.
Side note for anyone else starting this process: The Win PE 4.0 networking drivers (only has SMSC sub folder) aren't enough to get the proper device driver for the usb to ethernet in the version of the Elitepad I'm working with. I took ALL the drivers (broadcom, nxp, qualcomm, and smsc from the Windows 8 Elitepad x86 Driver Pack) and added them to the boot image and it allowed me to start the task sequence (aka: get past 'Preparing networking connections' in Win PE).
For the guy that posted his step by step, it is appreciated! I'll attempt those steps and scrap my currently deployment attempt including dumping all drivers and my captured image (didn't have the Windows 8 KB in it).
For an "enterprise ready" device, this elitepad via sccm insanely nitpicky about it's setup... (To be fair, Windows 8 is as well. Lets hope 8.1 is a major improvement!)