What is the average amount of times an android phone gets an OS update (excluding minor updates like 2.3.4 to 2.3.6)? It my very limited experience, I have noticed that outside the Nexus phones, phones only get one upgrade for the life of the phone. Phones that started with 2.1 got upgraded to 2.2 but haven't gotten 2.3. Phones with 2.2 probably won't get 4.0, etc.. Is this a pretty good rule of thumb?
I am eligible for an upgrade now but I hesitate to get anything that currently has 2.3 because I fear that even though it might quickly get 4.0 it won't get an upgrade past that. I can't afford a new phone on a regular basis so I need one that will last.