I do frequent the Avenger forums at times, just lurking though. That forum centers around the Avenger products mainly, which by the way is more or less rules-less.
What I try to do is to focus on the setting in its self independent of product and the original TNE rulesett which do have some followers. I have never been to the Yahoo group so I can't comment on that, but I got the impression of it being a mail-list and not a forum. The advantage of a forum is that it is divided into topics so you don't need to read or receive messages about topics that does not hold any importance for you.
I do not expect that my forum will be a big hit or take over other forums. I frequent this forum quite a lot because I like many of the discussions, however I find it lacking in the TNE department.
That said, the forum may change as I do anticipate what T5 holds, however from the stuff I received in the mail yesterday I am not sure I'll switch completely, but adapt it for TNE use (setting and/or rules) as I find fit.
I agree with Droptrooper that TNE 1248 doesn't feel like TNE, but it does give a few good ideaas about how my TNE campaign could develop if it runs long enough.