For starters, they could try to get the spacing in and between UI elements right. For example, the text in drop down menus looks pretty misaligned in those screenshots.

That's the first thing I noticed on their homepage, the spacing looks off to me too. It's a matter of balancing tension between visual events, not something you learn in high school art class ;-) On the other hand, I'm usually on a laptop and want to cram as much information as possible into a small space. I love how Gmail has cozy, comfortable and compact modes!