I see a 170 replacement having the 1920x1080 CMOS chips and flip-out monitor from the 370, fixed lens, capable of AVC-i recording onto P2, instead of going the AVCHD route (like the AF100). It would have stiff competition from the XF305 and EX1R/3, but with full raster chips and AVC-intra codec, it would hold its own. Of course, with these type of upgrades, it would be more expensive than it is now, too.
Just my opinion.