To answer your question my specific situation goes back to the old yahoo groups before there even was any real "forum" software. You see, we've had our community evolve through 4 different versions now going back to 1999. First it was phpbb to replace yahoo groups. Well, we setup picture forums as there was no Gallery as part of that package. We converted to SMF (7 years ago) which had a gallery via MOD but it wasn't as solid as we liked and our community was already locked into forums as a way of life.
Now that we have IPS which comes with a really fantastic gallery, I talked it over with my mods and we are really torn up about the right approach. We know our users will still want to use the forums but we think the gallery has a lot of potential. We like picture forums because posts with pictures foster a threaded conversation about the respective pictures. This we like. However, the gallery has a lot of added functionality. As it is now our forums are centered around pictures but we want to use gallery and can't figure out how to smoothly marry the two. We want to easily find all the image content someone has posted to the website without having to search for fragmented content in two different apps.