"Open" is not the same as "free" or "unencumbered". Devs are probably NOT flocking to make facetime video chat apps because Apple has a long history of banning apps that "duplicate functionality".
Apple also likes to play hardball with their stuff (in this case, their facetime protocol, their servers and their device users). If I were a dev looking to make money or grab market share, I do not think that iOS would be among my initial choices for targeted platforms because an integrated solution for video chat already exists there and the users would be unlikely to give my product a shot.
You're completely correct that "open", in the context of standards, doesn't necessarily imply "no-fee" or "non-patented".
However, "open"
does imply providing a uniform, RAND (Reasonable And Non-Discriminatory) method of:
1) Collecting fees from everybody who wants access to the standard, and providing the complete documentation related to the standard to everybody who pays the fee, without playing favourites in deciding that some people are "allowed" to pay the fee and access the documentation, and others are not allowed. (If any fee at all is required to access the standard.)
1a) If no fee is required to access the standard, then openly distributing the specification to everybody for free, without playing favourites in deciding that some people are "allowed" to get the standard and others are not.
2) Collecting fees from everybody who wants permission to make use of the patents or other proprietary intellectual property which may be needed to apply the standard in the implementation of a working device, without playing favourites in deciding that some people are "allowed" to pay the fee to license the technology, and others are not allowed to obtain such a license. (If the standard publisher owns any of the patents or other related IP that may be related to the standard. But keep in mind that any 3rd party patents may still need to be licensed separately from those 3rd parties.)
2b) Similar caveat as (1a) above, if no fee is required to access any publisher-owned IP related to producing a working implementation of the standard...)
An "open" Facetime standard would be a standard that gives licensed (either for free or after paying a fee, as noted above) 3rd parties permission to write their own ground-up re-implementation of Facetime for other platforms (such as RIM or WebOS or Android or Windows) -- which are fully capable of carrying on seamless conversations with Apple's own in-house Facetime devices.
