Direct SIP trunking has existed since OCS 2007 R2, however, WorkSpace Communications claims to be the only hosted Microsoft OCS/Lync Provider to support direct SIP trunking in a "hosted" environment. Even the more recent version Microsoft Lync cannot do direct SIP trunking when using a hosted Lync provider. I stopped by their booth at ITEXPO where they told me that Microsoft said it would be near impossible to offer direct SIP trunking in a hosted scenario. Well, they figured it out and are now applying for a patent.

Currently, WorkSpace Communications is hosting OCS 2007 R2, but Lync support will be released very shortly. They can host soup-to-nuts, including Microsoft Exchange email, Microsoft OCS/Lync with IM, audio, video, and web conferencing and SharePoint. They also offer PSTN termination using the Lync client at I believe they said was 4.9 cents/minute. You can also order à la carte which services you require, but for the full soup-to-nuts it's only $65/user per month. Not a bad price to get a fully hosted unified communications (UC) offering.