Although I would definitely be happy if the i760 for Verizon (hence CDMA) did not have an antenna, I somewhat doubt this will be the case.

The pictures of the only i760 we've seen so far are those of a GSM version.
Look at other devices that "lost" their antenna: the Treo 680 & 750 (both GSM only) whereas all 700's (CDMA) still have one, HTC Wizard/Apache (Cingular 8125 has no antenna, whereas the PPC/XV6700 still does), etc.

Therefore I have a feeling that the CDMA version of the i760, if it ever comes out, will have an antenna again.

As for other features, I think it should definitely include EV-DO Rev. A to make a worthwhile upgrade from the i730.
The i700 only had 1xRTT, then the i730/830 came out with EV-DO Rev. 0, so one would hope the i760 would feature EV-DO Rev. A - especially if its GSM/WCDMA equivalent is already HSDPA-capable.

-Marc