You must have flunked math, statistics AND logic.
The time that passed between April 22nd, 2005 to February 21st, 2006 is 305 days. If you continue that pattern then the next release would be 305 more days later--which is December 23rd, 2006. But wait...
Now since only 2 points have been established--4/22/05 and 2/21/06 as prior release dates--then there is NO definitive pattern established as nothing repeats. It would take a minimum of 3 points to establish a pattern. For example, 1, 3, 5. Then the next would by 7. Or 1, 5, 7 and then the next would be 11.
If you had two points--for example 1 and 5 how would you know if the next point ADDED or SUBTRACTED or DIVIDED or MULTIPLIED the 2 previous points or some other pattern? You can't.
So 1 and then 5 could be followed by 6 or by 5 again or by 9 or by just about ANY number actually.
Thus the next camera release could be subtracting 305 from 365 or 60 days from 305 days (245 days) and this would be a release date of October 24, 2006. Or it could possibly be April 22, 2007 as you have postulated (which is just ONE possibility of an infinite number).
You have simplly postulated ONE possible date using a non-exisiting pattern (an assumption). The actual date cannot be determined with only 2 points unless you make an assumption--which is a 3rd point in an of itself.
Sorry to burst your bubble!
So it could be anytime!!
Or not.