If you can afford them , the AVCHD models can record Standard ( not low

)
Def probably as well as the Non- hidef Models
Although this applies more to HDV vs DV it probably still applies .
1)It wont be too long before you get an HDTV.. there arent many which are not HDTV these days. The HD footage does look special on these Displays
2)You can record AVCHD and still output to SD mpeg2
after editng, the caveat being that the AVCDH editng software is all new and the PCs needed will need to have some "oomph". With HDV things are easier in that you can output HDV directly as SD DV
Otherwise, Just buy a non Hi def model and enjoy it for a few years, by which time the AVCHD models will possibly be less costly and the Hardware and software would be a lot more commonplace