bbPress 2.6 was initially scheduled to be released almost 2 years ago, and it was available since last year in the Release Candidate stage, and stable version has been finally released yesterday.
I have been using bbPress 2.6 for this whole year on Dev4Press Support forums, and for the development of Dev4Press plugins for bbPress, and all Dev4Press plugins for bbPress are 100% compatible with bbPress 2.6.
Some plugin has features specifically made for bbPress 2.6, including the GD bbPress Toolbox Pro and the admin side management of subscriptions and favourites.
If you notice any issues with any of our plugins when updated to bbPress 2.6, please, open a new topic in support forums. And, already there will be a minor 2.6.1 released very soon to fix few bugs that 2.6 has.