All of the caps i have from older Construct versions still work (although they were made using version 0.90 at the earliest) so im sure they will continue to, although if Ashley changes something at the core of Construct, or just something you used, you might need to replace the object in the old version to load it in the newer versions. But that is just my idea...
EDIT: its mostly dependant on the idea that you can complete whatever you are trying to make with the current version of Construct, if not, then I would wait until a new release comes with the features you want to use...