if you want bboards features (categorization, list of recently answered questions, etec.) use the bboard package on 4.6 - it hasn't gone anywhere and works great. If you want forums features (integration with notifications, better graphical customization, threaded views) use forums on 4.6. If you want the features of bboard to be present in forums please feel free to contribute the code needed to do this... your first and second points shouldn't be hard to implement (especially the second one that would be trivially easy), the third one may be a bit trickier.
