Which format(s) do clients want?
I suggest shooting at the highest resolution and highest framerate possible.
And progressive if at all possible, not interlaced.
Then you can offer smaller + slower framerate versions as well, by doing a down-conversion.
With my HVX200 - I always shoot @ 1080-30p, UNLESS its something that I want to show in slow motion(in which case I shoot @720-60p-<but only because my camera cant do 60 progressive frames in1080>), or Im wanting to do a massive undercrank (like 12fps or somit).
So as a rule of thumb shoot natively at the best format possible.
As far as HDV is concerned...Im thoroughly unimpressed...
Mainly with how HDV performs in post,-which is why I sold my JVC-HD10u (I know, I know..not a fair comparison of HDV v.s. DVCPROHD because the HD10u was one of the very first HDV cams) but even with the Canon XL-H1(think thats right) I prefer my HVX200's favorite picture quality. (not to mention all the other sweet features the cam has)
Ok, Im rambling now..