Gekko: I have exactly the same dilemma as you. I have been very happy using a MBP AG early 2008 for the past 6 years. I upgraded the machine to 4GIG a couple of years ago - makes a big difference to the speed - it can actually be upped to 6GIG ram. I love this machine - it's ergonomic keyboard, ports on both the left and right hand side, weight, design, it's a classic. Never liked the black keyboard on the new MBP - yes the case design is a thing of beauty but not exactly practical esp. with the ports all being on the LHS. Was very unhappy when I heard Apple decided to drop 15" MBP AG option last Autumn.
Last week I ordered a MBP 15" AG 2.6/8/500 from Apple's refurb store (they do come up but sell very quickly) and I'm in the process of trying it out before I decide whether I should keep it. The screen being AG is great - no reflections - it's a slightly higher res than 1440 x 900 @ 1680 x 1050. Not sure if this res is that useful, it gives you a little more floor space but it makes a lot of the type menus just a bit small for my eyes. You have the option of lower resolutions but not 1440 x 900, none of the lower resolutions are very useful. The machines speed is fast, but it's no MBP retina speed. The positives about the machine are: at least 25% cheaper than a 15" retina, AG screen, CD/DVD drive, longer battery life and faster speed over old machine, RAM is upgradeable and so is the hard-drive .
So today I went to Apple store to have another look at MBP retina and MacBook Air. Quickly dismissed Air. Considered 13" MBPr but I think the 15" screen is a better investment as I mainly do graphic design work. The 15" is a very nice machine, it is fast as hell, almost instant in many tasks. It's lighter, but that doesn't sell it to me. And the screen: colours are rich, it is sharp as hell, all of the different resolution options work perfectly, the big problem still is the glare. Yes it's improved, it's does not show reflection like the previous models but it still shows reflections. Could I live with that? I honestly don't know. I think only way to know would be to use a machine for a few days in real world environment - if it drives you nuts then it's not for you.
Not sure what to do? the MBPretina is a fantastic machine - it's expensive, you're looking at over £2K to do it properly. If it came with an AG option I would buy it in a heartbeat.