I think you'll find there is a lot of repetition on DiscoveryHD, HistoryHD etc. As for rapidly increasing I would have to disagree. Increasing yes, but no more than that.
I haven't noticed this claimed vast amount of repetition on DiscoveryHD, NatGeoHD etc. I think that that may have been more true in the past but there are quite a few new series starting at the moment!
The main culprit in infinite repetition seems, to me, to actually be BBCHD!
Ah but no £10/month subs. Once you include the £120 per year for Sky HD it does add up over time. FreeSat HD will give you BBC, ITV and C4 HD for no extra cost other than a one-off outlay. That's a bit more than one and a bit!
Given the fact that it costs channels a lot to go HD the lack of any "HD fee" is always going to hamper Freesat HD channel growth!
Freesat has one HD-channel (with a lot of repetition!) in BBCHD plus "a bit" (ITVHD) now. No-one knows when C4HD may arrive (with its own "bit more"!)
Sky had added the excellent (for me!) EurosportHD and RushHD in the last few months - I would not like to be totally locked out of their future plans by choosing Freesat (given that they, alone, seem to see rapid HD expansion as their USP!)