This is incorrect. AIXI is "not computable" only in the sense that it will not halt on the sorts of problems we care about on a real computer of realistically finite capabilities in a finite amount of time. That's not what is generally meant by 'computable'. But in any case if you assume these restrictions away as you did (infinite clock speed, infinite memory) then it absolutely is computable in the sense that you can define a Turing machine to perform the computation, and the computation will terminate in a finite amount of time, under the specified assumptions.
Simple reinforcement learning coupled with Solomonoff induction and an Occam prior (aka AIXI) results in intelligent behavior on arbitrary problem sets. It just also requires impossible computational requirements on practical requirements. But that's very different from uncomputability.
Sorry, you are simply mistaken here. Go and read more about it before you say anything else.
If it's worth saying, but not worth its own post, then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should start on Monday, and end on Sunday.
4. Unflag the two options "Notify me of new top level comments on this article" and "