DVR connection to D-VCR

I believe the Mitsubishi will only accept 1080i digital connections from camcorders and specific digital tuners (Mitsubishi and maybe some others) via firewire. Depending on the vintage of the JVC you may be able to use firewire, YBR and/or component inputs from an appropriate digital tuner or camcorder. From what I understand, Pay For Channels such as HBO, etc. may not work. There have been some computer based interfaces avialable, but, they are a bit esoteric and are reputed to be a bit "buggy". The last time I checked, which was sometime ago, there was only a couple of DVR's that permitted this output, was not available from Direct TV, is no longer in production and are actively sought out by others for the same reasons you've outlined. Many end up downgrading to analogue to archive. I could be wrong, but, some of the firewire connections may be limited to video.

To the best of my knowledge both the Mitsubishi HS-HD2000U and the JVC HM DH3000U can only recieve 1080i digital HD via IEEE 1394 fire wire. The Mitsubishi HS-HD2000U can only send via IEEE 1394 fire wire. The JVC DH3000U is equiped with an MPEG encoder/decoder which can upconvert analog signals to digital to record in the digital domain and output via HD analog component output. I'm guessing the JVC's MPEG decoder is MPEG2 and I don't know how it will interface with some of the newer MPEG 4 systems. I believe some of the newer JVC machines may be more flexible, but, I'm not sure. Unless one gets into some esoteric computer based equipment, I believe the only way to record in pure digital HD with either of these machines is via IEEE 1394 fire wire. This IEEE 1394 fire wire is only capable of connecting with specific applications.
If the HD Dishnetwork has an appropriate IEEE 1394 fire wire outlet, your probably in luck, if not, your probably out of luck.
I suspect the powers that be, arranged this mess to protect their "intellectual property". You know, reality shows and the like.

The LST-3410A is interesting. Too bad it doesn't have a high quality input connection to attach to a satalite or cable box. What were they thinking?
BTW, I don't believe you'll be able to use the Mitsubishi to play pre-recorded commericial studio released HD DVHS tapes, that seems to be a talent unique to the JVC.
So many options and so little compatability. Don't you just love it? These electronic companies must stay up till the wee hours devising ways to screw with consumers. This much confusion couldn't ever be possible just by chance.