I would send an email to HTC! Right to the top! I would tell them something like this " I bought this phone, but can not use it! My question ist: is there some kind of an update coming which will change my situation, or not? If not, I am forced to buy another phone (Lumia 620). I would like to have a clear answer. Thanks in advance..."
The thing is that you can not just hope that an update will come... If you knew for sure that something like that is going to happen, I am sure you would wait...but I doubt that HTC will give you some clear answers...