I watched it with my wife last night also.
There were moments of genuinely funny stuff and discussion, but it was a bit thin as mentioned. I think Lenny Henry's comedy is "Old School" now, and it shows. That's not really a criticism of him at all,I like Lenny Henry, it's just that time moves on and leaves you behind eventually.
I think he's a much better actor than he gives himself credit for, and probably has a good later career in straight acting if he were to allow himself, and if he worked with good directors. I somehow doubt though that he will let go of his "I'm Lenny Henry" persona, as he probably thinks that's what defines him.
Regarding the comedy aspect of being a black man in british society, I also think this is outdated now. My stepson's best and oldest friend (20 years for a 24 year old) is black, and my stepson literally does not see anyone as being different because of their ethnicity. Different for many other reasons, attitude, style, upbringing etc.... but not colour. To him race based humour is propbably a very odd and old fashioned concept.
I'm not sure last night's program did Lenny any favours. We also watch Later with Jools Holland as we love all forms of music, however every now and then a very old star comes on for one last show, and often it's a sad thing to watch as the voice has gone. Andy Williams was one, it was painful to watch.