FWIW, Micon discussed this several pages back. It seems they hadn't planned on html5/browser client being so valuable to people. When polls and discussion showed them how much people wanted it, they said the'd eventually do it but I think it's at the end of their list.
Should actually be on the top of their list, and should have actually been the first one to launch, since I believe the html client already existed on the previous site which had the same software.
HTML client essentially will allow all operating systems to play, whereas now its only limited to Windows.
HTML client should definitely have priority over mobile.
Have to agree, there are definitely a few waiting for browser interface as I am one of them. I will keep dropping by and hopefully it won't be to long into the future because this is by far the best and most trusted site I would like to play at long term.