When we were planning our kitchen remodel, one of the controversial elements was the corner window, and the corner kitchen sink that we put there as well. There was one main reason I put the window there and you can probably see what it is from this picture:
Those bright purple blossoms you see outside the corner window are some particularly fragrant lilacs. The bush is huge, probably 15' x 15'. Maybe more. I would open the windows to let in the scent, but here's the thing. My mom had suggested doing crank-style windows, but I wanted mullions, so we went with the sash type window. It is ungodly hard to reach them to raise the window, given their positioning in the corner.
However, I still love having the windows there. I just have to get up on a step stool or use a piece of 2 x 4 or something to push up the sash. The sills make a nice place for starting tomatoes, as you can see. Its also a temporary home for a couple of succulant house plants the kids begged us to buy them last time we were at Lowes.
So if you are remodeling your kitchen and thinking about putting in a corner window, I would say go for it. As far as the corner sink, bear in mind that you may get wet when doing dishes, and you will have to reach forward more than you would at other sinks. On the other hand, you get that nice span of countertop behind the sink to set your dirty dishes on when you clear the table, a little extra space that I find comes in handy on many occasions.
And if you have a nice view out the corner of your kitchen, all the more reason to put in a corner window!