In my opinion. Yes. Why not?

New technology is always evolving. VoIP is already threatening the landline markets... look at BT starting to offer it. If they don’t all jump on the band wagon soon then they'll be going to the graveyards.

The mobile market is going to be harder to crack. Having said that, all it needs is a mobile technology better than GRPS to come along, and VoIP with take hold there too. There are of course "mobile" phones available at the moment that run off wireless networks.... although that doesn't count in my opinion.