I am an engineer for Deere supplier that makes the SCV's for the 4710 and the Fifty-Twenty series. We have been producing a new 3 spool SCV for the 4710 (or 4020 I guess) for a couple of months now.
Deere will go into production with the new line (5025) in November. You can figure they will be available in the December time frame. I won't go into details, but there will be a new electro-hydraulic SCV and new mid and rear mount 2 and 3 spool SCV's. I have seen a test tractor that was intentionally mis-labled. I would have gotten to play on it, but it was almost out of fuel /forums/images/graemlins/mad.gif