My guess is that retina support through Athens rendering and 64-bit are critical to greater adoption of Pharo for several reasons: (1) First impressions matter greatly. If I try to get someone into Pharo and the first thing they see is a pixelated screen, they will have an immediate bad reaction. My students believed that Pharo was a toy language because of the pixelated rendering. Even when I explained why, I'm not sure they believed me (sure, prof, we believe you). The interface being slow also gives the impression that the entire system is slow. So, speed improvements from Spur are less tangible. For most newcomers, interface speed = system speed. (2) One of the first things newcomers will want to do with a new system is some sort of graphical user interface. Pharo's morphic is quite nice but the BitBlt rendering is off putting. So, even if newcomers buy that there are reasons for the rendering being not great, they will likely conclude that it isn't a system for them. (3) The vast majority of OSes are 64-bit and 32-bit packages are getting deprecated. So, even if there are nice ways to interface with the outside world, they are being held back. So, very small things, like sound on Ubuntu, don't work. It's not really worth fixing that until Pharo is 64-bit. Again, it looks like Pharo is behind the curve, rather than ahead of it.
Now, that stated, I understand why things are the way they are. There are limited resources and there are things that take priority. In addition, there is the tension between Pharo as an engine for research ideas (roughly equates to the things where Pharo is ahead of the curve) and Pharo as a general purpose environment (most notable in places where Pharo is behind the curve). Pharo5 is a major accomplishment and I am excited by it. It is awesome what was accomplished. I have faith in the leadership in setting priorities and great appreciation for those putting in the time. My point in posting this is not to criticize past development or priorities but just to make the case that these two things on the horizon (retina support, 64-bit) are important to my use of Pharo and how newcomers will view the system. I wish I could contribute but the VM things are out of my zone of competence. Cheers, Jeff