I highly doubt this. The people that properly play RS07 do so because they do not like EoC. With RS3, the gameplay is exactly the same, just with improved graphics, therefore there will be no reason for RS07 players to return.
I was under the impression that this is not the case? When RS07 was first released then sure, but as far as I can see, the population on RS07 is dwindling, there certainly isn't a vast number of players moving from EoC to RS07 any more.
Eventually you will ^_^ I personally much prefer it, especially the fact that the combat triangle now works properly once more. It adds a lot more strategy to PvM and PvP in my opinion. The option to switch to momentum and train the old way is also a nice touch.
It will be worth it if you enjoy it, that's all there is to it really. With it being so easy to achieve the end game on RS07, as well as being too easy to earn enough money to buy whatever you want, I personally don't see any longevity in RS07, even PK'ing gets boring after a while when you realise just how many PJ'ers there are