I don't have a 13" laptop, but when I did, I wanted a higher resolution than 1200 x 800. Honestly, this LED backlit screen on my current mbp santa rosa is outstanding. The colors are brilliant, the lighting is perfect, the viewing angle is perfect and the resolution is good enough for me (1440x900).
As far as the processor is concerned... just make the jump to the ix series already! i5 would be good enough for me.
The hard drive should at least come at a stock 7200 rpm's (as long as any excess vibrations and noise can be dealt with easily) and nothing lower than 250 GB (wishful thinking, I know. But it is a PRO model after all).
I could care less about Blu-Ray at the moment. I have a Blu-Ray player hooked up to my HDTV which is good enough for me.
The graphics NEED TO BE UPDATED. I would love a discrete nVidia card, but I'll give ATI another shot despite my bad experience with them.
MORE USB PORTS! Most laptops of the same price have 3 to 4!! wtf Apple? And please, keep firewire and 2 audio ports (line in and line out).
That's about all I can think of now.