At first, VoLTE will be used to deliver "Rich Communications Services" (which look like something similar to what Voice over IP/Video over IP outfits offer today) rather than completely replacing narrowband voice. It will be awhile before Verizon is willing to commit to that, due in part to LTE outages in late 2011.
On the flip side is MetroPC, which has pushed VoLTE as hard as it could.
Then there's Sprint, which will stick to voice over 1x for the foreseeable future, but routes Direct Connect over IP. Sprint's latest DC incarnation seems quite similar to one facet of RCS over LTE.
When I think more about this merger now that we're approaching April 1, I think back to these old Sprint advertisements and how things have turned out since.
These are first rate ads, and they certainly rival anything that the other three carriers put out there. However, this merger was bound to happen when these advertisements were better than the actual network. The icing on top was great, but the cake was falling apart underneath.