While the link above is to a rather long and detailed post at Consortiuminfo.org, I found it very informative on matters of patent licensing in regards to software standards.
The subject of the post is Microsoft's promise not to assert patent holder's rights against implementers of a proposed standard. Essentially, this means that while MS has the patents, they won't sue anyone using the technology in implementation of the standard in question.
Like I said; it is complex. But this will go a long ways towards clearing up any questions you might have on the subject. It is very well written and quite understandable, which is refreshing.