Agreed about SSD being a game changer. I literally gave my 2010 Macbook Pro new life with a 960GB Crucial SSD. Even without TRIM being enabled, it's been a godsend. Startup went from 2 minutes to 20 seconds. And I've got so much media on my SSD that it constantly fluctuates between 75-90% full (and then I offload the projects I'm working on to an external HDD).
The only reason I want a new laptop is for retina. Now having an iPad Air for work, it seems like the pixels on my MBP are even more pronounced than before! And being part of the Yosemite beta, it's easy to tell that the fonts and UI have been tweaked to really take advantage of very PPI displays. Yet I also want a light form factor for my next laptop. I read that the MBPs will be slightly refreshed with the recently refreshed Haswell chips, but that the bodies will stay largely the same, which is still a pound less than my current MBP, but nowhere near the Macbook Air. Ideally Apple would have come out with that rumored 12" MB Air/Pro combo, which was supposed to fall between the lines in terms of power and size/weight, but also have a retina screen. I think that's been pushed back to wait for the oft-delayed Broadwell chipsets.