If your final delivery format is SD DVD then you should shoot the weddings on a camera like an SD camera like a Sony PD170 which has good low light performance.
HDV wont make SD output look any better and the trade-off for high resolution is reduced low-light performance.
The blurring issue sounds like JVC’s motion smoothing option for 30p. If you turn it off you will have a ‘filmic’ strobe effect. Again you may as well shoot SD 60i and create SD 60i DVDs. Motion will look smoother but not blurry, and progressive displays will just de-interlace it as needed.
Nils
(PremPro2, WinXP P4, 3.2GHZ, 2GB RAM, 500GB RAID-0, DV/HDV)