It was a stupid move
why SD card slot?
expresscard slot is more useful and expandable
not all people want to carry a 17" out
.... and not all MBP users are professionals carrying different I/O equipment, HD's, cameras, portable raid arrays, audio processors etc. etc....
Honestly think about it for a second, Apple has been making this shift to be more tailored to the "consumer" because that's where their market is.
Many consumers only use a point and shoot camera which uses a SD card, a lot of consumer video cameras are using AVCHD which is stored on a SD card.
Putting a built in SD card slot pretty much eliminates all issues for the end user when they want to get their photos or video off of their devices.
From a end users perspective, think about the steps to get photos from a camera into the computer. first they have to get their 3 foot USB cable, then connect the camera to the computer, but wait.... what if the cameras battery is dead? then you have to find a power outlet and connect the AC adapter to the camera. Though you could use a express card reader, its just another device that you would need to carry with you just to get pictures off of your camera and the fact that they would have to do some searching just to find out if a certain express card reader even worked in OSX. It's easier for the average consumer just to have that slot built in.
Now I feel for the DSLR users who use CF, but then again that's the way Apple is changing it's product line, by tailoring to the consumer. This shift was even apparent when they first released the unibodies, now it's heading even more in that direction. If Apple really cared about it's professional crowd, then we would see a 17" notebook with workstation graphics, at least 2 HD's and a plethora of ports including eSata.
If Apple tailored to everyone and gave them whatever ports they wanted eSata, CF,and MS in a 13" package, we would be have a big clunky notebook much like our PC counterparts.