I find it significant that the leaked A77 pictures both feature the battery grip, and I think I can see why.
The A77 has a compact body and might be significantly smaller than its competitors. It’s important therefore for Sony to communicate that, whatever size, it is a serious ‘professionally-minded’ camera. And what better way to do this than to show it first with the battery grip.
Personally I don’t care for the grip and the smaller they make the body the better. But I can see their thinking from a marketing point of view.
Sony Alpha A77 - With Grip