Several quick - first impressions/comments:
a) "Look" sure is different - too soon to know if this represents an improvement.
b) The forum user's ID no longer is displayed. (past high - atop first page) This is a weakness as you're unsure if you've "signed-in" to post or have suffered net "drop out."
<edit> 07 Dec, 09:26 - find now that, "User's ID/Nickname" now appears at the top of page, rightmost small icon, but requires "mousing" to that icon to reveal. Past method "spelled out" the ID - no such "extra scrolling effort" was required...
c) Each post now reveals (only) the originating poster's ID & number of responses. This too proves a weakness as involved posts often key on "back/forth" responses - which are now revealed only by the (cryptic) number of responses. Not good!
d) Note too - the loss of, "Conversation" alert which past was resident atop - first forum page. How are we to privately converse? (that's BASIC - is it not?)
e) New forum design has "lost" the ability to, "jump to a specific forum page!" Long ago I requested this be added - and it was. Now we scroll one page @ a time - or jump to the last page - that's it. Appears "retrograde on full parade" - past forum "methods/madness" discarded - perhaps w/out clear understanding of their value...
f) To be fair - we like the new, "Recent forum questions & discussions" drop-down box (atop the forum) - this is a nice plus!
Forum changes were made w/out input by any of the (outsider) forum community - to my best knowledge. (checked w/several) Of course that's vendor's "right" - yet these obvious NEW Forum "weaknesses" may have been prevented if the community was given the opportunity to "preview & comment."
Hopefully other forum users will arrive - add their impressions. Overall the changes appear not overly positive... (and those negative effects could have been prevented!)