Re: will lumia 720 get the new update? ( windows 10)
If your question is "Will Lumia's get Windows 10" then the answer is YES, MS have said all Lumia's will be upgradable.
On that basis I would also guess that most other current Window's phones (WP8 and above) will also be upgradable but that is a question for other phone makers and possibly carriers.
But the fact you go on to say "Can't wait", would suggest you already knew the answer, but just want to chat about it.
On that basis I would suggest joining the community and posting under your own name rather than using the "Ask a question" function.
It's a friendly place with lots of knowledgeable people who like to chat.
And I had better add, Windows 10 is not due for release until late summer 2015 so still a good few months away, there is no time frame for when the phones will get it, it would be nice to see a global release on a worldwide and device wide basis but for now we just have to be patient.