Your blog post is what inspired me to post here as well as Frank's comments.
First, kudos to you and your team. I know it can be a difficult thing to pull off a change-over of this magnitude. I for one, hope that it will be worth it.
Secondly, I have been a member since October 2008. Yes, that is no excuse for me having little to no involvement. My post count as of today is less than 10 BUT that is changing.
Thirdly, the Signatures. I would keep them but at a minimum just allow Text only rather than the dolled up versions. Keep them simple and family friendly. Period.
In my niche I am a trainer. I give out tons of FREE help and I do not ask for a nickel. So when someone clicks on my signature and ends up buying into my training program. That makes my time worth it.
I can only speak for myself but I do click on other members profile pages just to see if there is anything deeper to the person. Many times there isn't but I do fear that totally eliminating signatures will drive away some of your users who are givers to the community because like me there is some payback that comes back to us.
Please don't take my comments as a gauntlet being thrown down. I will try the new platform but for me even a decent hint at making a buck by way of a simple signature is important.
Thanks for your time and I really do wish success with the new roll-out.