Thanks for the responses, I thought the thread was going to die without a peep. (Koffee, Nathank, Velocipedio... where are you???)
After trying it for a week, I'm developing some opinions with regard to recovery. I think the hard running intervals are using up glycogen, so I'm having trouble mustering enough steam for lactic threshold intervals on the bike. The other variable is that the running intervals have increased the running intensity quite a bit relative to what I'm used to, and it'll take some time to adapt to that.
I think what I'll try next is to dial back the intensity on the runs, except maybe one day a week, on a day before a longer, slower ride. When my legs can run handle running harder without feeling stressed, I might try working one or two intervals into a second weekly run and see what the effect is.