It doesn't matter if there will be suites labeled 2011 in 2010 or not. If no 2011 product exists for the app in question , nobody will expect you to say you are using it.
Under this premise CIS 4 will do as much well as CIS 2011 or CIS 2012.
Indeed according to the above assumption it wouldn't matter if the version got a single digit number or a year as long it is the highest number available for that product.
Also, none of the vendors who use the yearly name format bring out a version with the next year's name before June at the earliest. It is always in the second half of the year and sometimes not until the third quarter when these products start to appear.
Year numbers are a much more easily discernible way to determine a product's age than it's version number. Only those already in the know will be able to tell by a product's version or build number.
Guess as per you above premise the year is not relevant to discern the most recent version
of a vendor's product as indeed users have only to get the one with the highest number as you mentioned.
Guessing the product age from an year would be something different from getting the latest release of a specific product whereas since the year version bring forth age related conjectures
it means that an user could get the next CIS major version and consider it as much new as the others 2010 suites or, once other vendors release their 2011 version in 2010, even older
than other products regardless
how much little difference there will actually be between the release dates.
Considering CIS 4 is seemingly scheduled between latest 2009 quarter and the first 2010 quarter I wouldn't care the less about the time when few other vendors will issue their yearly releases but I would find disappointing for those users to misunderstand V4 as something as recent as
the other 2010 suites around the time it will be released despite being a more _recent_ product.
Another thing is that vendors can give their products any version number they want and make it appear that the program has been intensively developed. You can't call someting XXXX 2015 and get away with it.
It wouldn't make sense to call 2010 whatsoever product released in 2009 either, though it happens all the times... before the users will get to see 2010 on their agendas/calendars...
...and before a new major version will be actually released in 2010.
Besides as long an user won't get particularly interested in vendors specific release patterns, something seemingly unlikely, as a rule of thumb all they have to do is subtract one from the version number to guess the year of release disregarding the month.
Why should they make more than that for a version number whose purpose so far was supposedly meant to have them take it easy?