2560x1600 on Dell U3011 with new MacBook Pro I have a brand new MacBook Pro (Mid 2014) and a Dell U3011 30" display.

Is there any way to get the full 2560x1600 resolution on the Dell without the $100 Dual-Link DVI adapter?

I've tried HDMI to HDMI and Thunderbolt (Mini DP?) to HDMI, but I can't get more than 1920x1200. I've also tried resetting NVRAM/PRAM.
Try using the mini Display Port to the Dell's Display Port.
That's how I connect to 2 2560*1440 Dell screens.  

I've found, in order of reliability  


Display Port - works every time  
DVI - works most of the time, can be fussy on some screens  
HDMI - haven't used  
anything  > VGA [barely works at all on anything over 1920*1200]