To me, the need for the Nexus is best summed up in one acronym: LTE.
My current phone is OK and not yet dying yet, I'm just sick and tired of T-Mobile's crappy coverage in my area (as well as upset about the potential merger with AT&T down the road). AT&T itself and Sprint are also bad choices right now.
I want Verizon's coverage, and since I want to switch anyway I want the best phone that will continue to get updates. A delay on that means more money going to Verizon's competitors, which neither I nor Verizon should want.
I'm fine with a (temporarily) buggy phone, especially if it has to do with calling. Ironically, I don't use my phone that much as a phone, I want to use ICS and have its features, not some Sense UI crap or Motorola's UI. So the Rezound and RAZR won't work for me, though they do look like nice phones. This probably puts me in the minority for Verizon's target users, though it's my understanding the Nexus line is supposed to be for developers, not particularly regular consumers - maybe this is a change of the target market for Google.
I signed up for the Verizon Nexus update mailing list and the only communication I've gotten so far is spam about the RAZR. I want more openness, not less. I'd understand if problems made Verizon push back their date. But to have *nothing* for this long after Google announced it last month and we were told November for release. Now it's possibly December or "end of the year". By that time it's almost Q1 and we're getting outdated technology. I just want the best phone on the best carrier for one day, and I feel like I'm being led along on some hype-machine (maybe that's in part due to my daily reading of this forum but leaks and speculation are inevitable in absence of actually talking to your customers).