Hey NYC... I'm working on the "lovingly detached" thing right now too, while living under the same roof. I'm going to post more on my thread in a minute about it, but for me the difference has been thinking of myself as divorced already. It has just completely changed the framework.
It changes how my W and I interact, how I view household management, finances, even how I interact with others. It frees me up to be me, not to be the depressed husband who's about to be kicked to the curb.
I've even thought of taking off my wedding ring. I haven't yet, but I've considered it. The only two things stopping me are 1) my S for some reason fixates on it often enough such as when he comes in the bathroom to ask me a question and I'm in the shower (Daddy, don't forget your ring!) and 2) I don't want to communicate that I've completely thrown in the towel. While I may be divorced/separated in my head I don't want her to necessarily know that. I don't know why that is though.
And maybe thinking of myself as divorced isn't the right words... maybe it's more as legally separated...
Married 6 together 8 Me:38 W:31 second marriage for both SS12, SD10, S6 Bomb: 9/8/11 (day before our 5 yr ann) W moved out: 2/18/12 D final: 11/12/12 Share S 50/50. Spend as much time as I can with SS & SD