Google just released a blog post detailing the current status of what is considered mobile friendly.
Key points are:
- Google Mobilebot crawls the web using feature phone user agent strings, NOT smart phone user agent strings
- Google does not consider it cloaking if you serve different content to their Google Mobilebot
- Whatever content you serve to mobile users should be the content in the mobile sitemap
- Redirecting to a mobile URL is OK (m.domain.com) as long as you use a 301 redirect
Here is the article – Making Websites Mobile Friendly