Short version: no.
Long version: well, it might be, if notoriously slow moving telecoms, many of which are struggling with profit drops *cough* Sprint Nextel *cough*, manage to join forces and create a worthy competitor, as suggested by ThinkEquity analyst Anton Wahlman.
GigaOM picked up the story, and they're also not bullish on the idea. Wahlman suggests that British Telecom, Deutsche Telecom, NTT, and about 10 others, are planning to offer a VoIP client (sometime in 2009) which would enable users to make free voice calls to other users of the software. However, since they're, well, telecoms, they could offer web-to-phone line calls at a lower fee than Skype because they save on termination costs.
The problem? Skype has currently got over 309 million user accounts. If they continue growing with the same velocity, they're going to reach 400 million by the end of 2009. It's not easy to catch up with Skype, and people have gotten used to it in the same way they're slowly getting used to Gmail as *the* email client.
Telecoms, like all giants, don't really have a choice (and they probably don't really care). Huge corporations are rarely first on the market, anyway: they can afford to be late and still hope for a significant market share.