Real-time hashrate and rejected percentage data is available on user pages. It's updated every minute and shows last 60 minutes in 10-minute intervals. It isn't very pretty but it's working. The user page starts growing so I think I'll split it into some subpages soon so that you don't load all this data when refreshing the page.

Hashrate stats update every minute, so for example at 02:55 the “-10 min” data shows data for 02:45 - 02:54, “-20 min” for 02:35 - 02:44, and so on. One minute later they will be showing 02:46 - 02:55 and so on.

Let me know if the above is obvious from the charts or should I explain it somewhere on the website.

Rejected percentage shows both your rejected and average pool-wide rejected. It allows comparing your rejected ratio to average ratio so you could tell if a sudden spike in your rejected ratio is something you should worry (if pool average didn't spike) or is it just some faster coin being mined at the moment (if pool average spiked as well).

This is how it looks: