I thought I'd at least get a slide telling me what happened to them!?!

I fell in love with the Brotherhood and completed their questline early on.

I then decided to serve Mr. House - and was a loyal follower until he left me no option regarding my brothers in technological worship except destruction: so Mr. House ate lead.

I installed Yes Man and went on my way - telling him to leave the BoS alone.

But nothing is mentioned about them from that point!?!?!

I feel ripped.

I think you can get a mention of them if you sided with Yes Man by convincing the Brotherhood to ally with the NCR. Yes, I know you are actually fighting for independence now, but convincing the Brotherhood to help the NCR during the final battle is essentially the same thing since you are fighting Caeser's Legion at first. They don't actually show up during the final battle sequence, though.

They do show up and fight along side you, if you fight for the NCR.
(A beautiful thing, BoS and NCR Elite Rangers standing side-by-side, at my back. Glorious.)
But if you choose YesMan, you won't see them at all.
When I fought for YesMan, they did not appear in the ending slideshow either... (as requested they were ignored!)
Regards

I went with the Yes man earlier on, did the blade of steel quest keeping the original elder, and Veronica's quest where she became loyal.

The ending said something about Veronica and her loyalty helping BOS becoming more agressive, but that meant their destruction or something. I can't remember now.