When companies start making real products for some other company's service, you know something is going on. Skype is beginning to make real inroads on the VoIP marketplace, and hardware manufacturers think there is money to be made.
XING is a conference phone made expressly to work with Skype and only Skype. Niche market? Yes, but apparently big enough to actually make stuff for it.
I'm not crazy about Skype because it uses a proprietary format, rather than an open standard. But it works, and because it has a business model aimed at making money, the company can focus on quality and good service. In comparison, I tried for a couple of hours to get Free World Dialup, a free, open source VoIP service, working on my computer. I'm sure it does, but the configuration was obtuse and the directions were lousy. I couldn't figure it out, and two hours is about my limit. And if I can't figure out in that time, a lot of other people with a lot less patience probably can't either.
Skype may not be the best VoIP service technically, but it works. And like the old Betamax-VHS war, we know you don't have to be the best to win in the marketplace.