I love my current 2009 15 inch MBP but I'm looking to upgrade the display. My understanding is that I cannot upgrade to a retina but is it possible to upgrade to a higher resolution than the current screen? I do a lot photo editing and would love to have a little better screen. I'm not looking to upgrade to a new MBP. I already have a new 27in mac that I use for editing but thats in my office. When I'm home and just looking to edit a few photos it would be nice to be able to use my MBP. Any help or suggestions would be greatly appreciated!!!
This is not going to be possible. Each display is not just a display, it's an entire display module and the whole module needs to be compatible (e.g. cabling connector and length, hinges, etc).
You could get more than the native 1440x900 resolution by using an external monitor (up to 2560x1600), but I'm sure you'd already know that.