I think a great feature would be allowing an "override" of the DHCP assigned DNS servers. I have had great experiences changing the DNS servers on mt Moto Q - Sprint from the sprint assigned ones (very slow servers) to the www.openDNS.com DNS servers, greatly increased my browsing speed due to the decreased time in URL resolution. The problem is that whenever my phone renews it's IP via DHCP it reverts back to the Sprint servers and I get slow crawling internet browsing again.
I would love a way to set things manually, not the whole thing as my IP address changes so having a static IP would not work, but if I could override just the DNS server so that it would not revert back on an IP refresh... now that would make my already good web browsing on my smartphone truely great.
This speeds up everything btw, web surfing, getting my email off gmail.com, connecting to AIM, pretty much anything that uses the data connection.