Photos sync'd to the iPad from iTunes can only be removed by either settings iTunes to not sync (and thereby removing them) or removing the photos on the computer and then sync again (removing them from the iPad).
There is no delete option locally on the iPad for sync'd photos.
GAHH, I'm having the same issue too.
If there's no delete option locally for sync'd photos, then what else is there to do? So far, the only option I have to get photos onto my iPad in the first place is to *sync* them, no drag 'n drop options to be seen - God forbid we make things easy. From there, they just STAY there until I manually uncheck them from the source (my MBP)? For real?
Yeah, I know I sound pissed
But come on, does this need really to be a painful process?
EDIT: There's the 'Manually Manage Music and Videos' option which allows for an easy drag 'n drop for both my iPhone and iPad, does something exist for Photos somewhere??