So for aggregation we definitely do some of that work already, we enable clients to aggregate their raw data with a few different methods, like via running a total, average or count, over any arbitrary time frame.
For us doing the actual calculation of the dimensions at a specific time, we haven't thought about it, but we're always interested in building more so we might be able to prototype something.
Your specific example though is sounds like another way of metrics to be pushed into our platform, this really wouldn't be that big of a problem for us to implement, and we even floated the idea around of us exposing a stream that clients could push data to which we would process.
Given that the logs would be in an open standard format, we could definitely do that and it sounds like a good idea. :) Thanks for the suggestion.