You get the best of both worlds - your eLicenser licence for WaveLab 11 and all earlier versions remains in place, plus you get a Steinberg Licensing licence that allows you to activate WaveLab 11.1 on up to three computers. Your eLicenser licence for WaveLab is marked as non-upgradeable as part of the migration process so that Steinberg’s systems know you have migrated to Steinberg Licensing.
There is therefore no reason to wait until WaveLab 12 to migrate to Steinberg Licensing.
Backbone licence migrations opened up today with the release of Backbone 1.5, which is a free upgrade for existing users. I have migrated my standalone Backbone licence today - my main computer is still on eLicenser, my Surface Pro now has Backbone activated via Steinberg Licensing.
The only reason I have yet to migrate WaveLab to Steinberg Licensing is because I received the wrong voucher (I received WaveLab 11.1 Pro Educational; my licence was Educational in the past but the Educational restriction has been removed by a paid version update). I look forward to having WaveLab on my Surface Pro once Steinberg sorts out this problem.