An MMO could run on even the most antiquated PC if it had the proper internet connection -- take MUDs, for example -- and graphical MMOs have been around since 1987. As far as technical proficiency, Liberty asserts that the console "could certainly handle something like EverQuest Online Adventures." Add the voice chat and we can see a modern MMO within the realm of technical feasibility.
Liberty's more notably asks the question, "would there be a market for a PSP MMO?" The problem we see is trying to make a portable MMO profitable. Could a publisher convince enough gamers to pay a monthly fee or find some other way to level server costs? Could the developer keep the world alive with updates and bug fixes? More importantly, despite all that, is there a big enough interesting in having a virtual world in your pocket? Let us what you think.
[Via PSP Fanboy]