Are most movies at their best possible quality in 1080p and on Blu-ray?

[vpt360]

I'm not here to start another thread about format wars or double-dipping. Rather, I'm more interested in learning a little about the maximum resolution that most (not all) movies are presented in.

In other words, if I buy a Blu-Ray of a movie today and it has true 1080p HD, then am I really viewing it in its best possible resolution (regardless of home-media or theater formats)? Or is it just the best that Blu-Ray can hold? For example, let's say that there is a 1440p version of a movie out there but it currently won't fit on Blu-Ray so the studio offers 1080p. Then is there a chance that down the line they will re-release it at 1440p or some other "higher HD" form?

Obviously many big-budget blockbusters of recent ('Avengers', 'Dark Knight Rises', etc.) are filmed in ridiculously high definition and clearly go beyond 1080p HD, but what about the majority of movies currently out there? Be it a classic from the 50's or an Oscar Winner from the 90's--are they available in their best possible viewing with 1080p?

I'm still kind of new on these boards and have been curious about this for a long time so I hope it's not too much to ask.