Someone brought up this idea in IRC today, would anyone be interested (enough to pay for) a 'personal' multiport, where you could select the coins you wanted to mine?
This was more along the lines of my original pool idea. Each user would be able to toggle checkboxes for each offered coin in their control panel. The switching logic would have to check profitability and the user-coins table every minute (or whatever), and redirect each user as appropriate.
*edit* I'd probably stick with the full selection of coins, and continue converting the ones I don't want to hold onto into BTC.
This issue should be solved. The script now checks to see how long we've been mining a particular coin, and if we have more than a threshold (currently 10 minutes), it switches to the new coin immediately.
This should at least partially solve the 'flapping' issues we've been having where the port switches between two coins because of very minute changes in price.
Hysteresis is good. You could just set a minimum difference between current coin's profitability and the best one before switching. Ex. Currently on FTC @ 1.60, LTC starts to climb higher, but we don't swap until it hits 1.65 (minimum 0.05 delta). Then we wouldn't go back to FTC until it reaches 1.70 (or LTC drops back down to 1.55).