Oyster's not going
Although the current iteration of Oyster may be approaching the end of its life, TFL doesn't plan to do away with it entirely; there is still almost certain to be a new generation of Oyster card, for various reasons. There are people who don't have a contactless bank card, because they have limited banking facilities, yet still need to travel in London; there are tourists who may not want lots of foreign exchange costs on their cards. The main change is that, in line with the way the contactless card processing is done, in the new generation Oyster everything will be worked out by the back end, rather than the card doing a fair bit of the work, as it does at present. There's more on this at http://www.mayorwatch.co.uk/much-delayed-but-tfls-contactless-rail-fares-cant-fail-to-impress/
A friend who works for TFL tells me of the problems with phones and pay by bonk so far is that they're slow - much slower than genuine cards. Whether that's the fault of the way phones handle NFC, or the ticket gate, I'm not sure. But it can apparently take longer for the ticket gate to react to the phone than to a card. Might not matter at a suburban station off peak, but even a couple of seconds on each transaction at a busy station in the rush hour could slow things down on the gate line.
Add to the fun that now you won't just need to keep your Oyster and your contactless card separate - you'll need to keep all your contactless cards away from the one you want to use to travel. I have two such debit cards (one business, one beer). Weekly capping is going to get lots of moans from people in a similar position if they don't realise that some journeys went on one card, and some on another.
Also, "penetrate the everyday lifestyle" ? Really? Back to your strategy boutique, sonny.