My formula is
fn-If(fn-Equals(Status,"Submitted"),fn-Replace(Item URL,"DispForm","EditForm")&Source=fn-GetQueryString("Source"),fn-GetQueryString("Source"))
The resulting URL (Site URL portion removed) is
.../Requests/EditForm.aspx?ID=43&Source=.../Requests/Submitted.aspx
Nintex has announced yesterday this functionality is nearing completion and they are aiming for a March release!
That's super exciting!
Annnnd it looks like "Save & Continue" is now released. WOO!
Which version? We are running Forms 2010 v1.11.2.0 and I don't see it.