VOIP service provider Vonage filed for IPO to raise about $250 million.

Vonage is supposed to have 1.4 million subscriber lines. The issue is that cost per subscriber is raising and Vonage is making losses. I am not sure if the IPO market is ready to take on loss making companies already again. Additionally as recent news about Skype loosing 50% market share within 12 month in Europe indicates the VOIP market is still highly voilatile.

Vonage hired Mike Snyder former President of ADT, part of Tyco Fire and Security. He replaced Founder Jeffrey A. Citron, who will assume the role of Chairman and Chief Strategist. I guess he has his work cut out: get profitable.
I am a Vonage customer since a long time. I am very please with the quality so far. The success of the IPO is not an issue of the quality of the product, rather about market share growth and revenue generation.
See also BusinessWeek's take on the Vonage IPO.

VOIP Offers:
Verizon VOIP Service “VoiceWing”
Vonage the Broadband Phone Company
ViaTalk - Broadband Phone Service