So we see here people with more then one iPad at home .
If you have a single account for both of them. That is fine.
You may install application on up to 5 different iPADs.
Nice as long as you have them all under one account (I think).
Now you have just on Directory of iTUNE on your computer
Located on my XP LAP top at : C:\Documents and Settings\USER\My Documents\My Music\iTunes
It is 1.5 Giga and it is only the application I synced with.
I synced nothing else (Pictures that also need syncing are in a totally different directory.

So .

I have copied all that directory from my LapTop to my DeskTOP as a backup.

Now if you have 2 iPADs with 2 different accounts, I assume you will have double that space to handle.

Any one can give us some insights of what he/she is doing in regard to having 2 Accounts for 2 iPADS on 2 PC's