There's a small but significant change being made to AdWords this week you should be aware of.
Google announced they will now display only lowercase domains in ads, for example "Subdomain.Example.com/Subdirectory. . . will appear as subdomain.example.com/Subdirectory." The change already has a few detractors and will doubtless accrue more, but Google has little cause to capitulate and gains more (like an increased overall clickthrough rate) by dictating how URLs are displayed.
This might also reduce the effectiveness of campaigns that use two and three word URLs, instead benefiting campaigns with single word domains. And as noted in the above thread it may increase the usage of descriptive directories in the display URL.
On the bright side, that's one less decision to make.