WTP is going to have a relaunch of some sort in the next few months, though I think the focus is mainly on food and drink, perhaps some improvement to blankets/pillows.
From what I see as an observer, WTP is now not very standard. The 787 and 380 WTP looks very smart and spacious (particularly the 380 version), the older 777s and 747s are quite another matter. We've seen some reports of the new LGW WTP product not being very good but I haven't seen that yet and I'm not sure there's an accurate comparison going on in these reports. The variation is greater than any other cabin, to my mind.
I very much see the rational behind WTP, however. If the cheapest way across the Atlantic is £500 (for the sake of example), then one may be prepared to pay "a few hundred pounds" to avoid the full back of the bus experience, but would draw the line at "a few thousands" of pounds. WTP is vastly more important to BA than First.