A good list is here:
http://www.zimbra.com/pdf/Zimbra%20C...ure%20List.pdf
Next version will come with 3.1 which is our next release. It's within a month. If you are having a specific problem and need help please contact our support team via the support portal. If it's a major problem it may be possible to get you a patch or work with you to get another solution.