It is as good as confirmed - Diablo 3 will be announced over the weekend. And add this to your list of rumours, it will contain the option for a first person view.
There is an argument for the original style of the Diablo franchise to be retained. More recent games such as Titan Quest has sucessfully pulled off the feat, but it is one of few. The most successful combination has been in games such as Dawn Of War and Company Of Heroes, where you can zoom in to a soldier level. Hellgate: London was touted as a first person Diablo but failed to live up to expectations, more through execution than concept. And it was the first person Diablo that got people excited. Isomietic certainly doesn't seem to work within this style of game. The smart money is on a first person view option from an isometric view.