Generally, for approaches steeper than three degrees, it's more a case of aircraft certification and approval rather than equipment.
Yes, I was using "equipped" in the wider sense.
I'm guessing that we'll be talking about TEAMed arrivals between 0600 and 0700, with normal 3° approaches on the other runway.
I suspect that "steeper" in this context will turn out to mean no more than the 3.2° approach listed under "Quieter operating procedures" in Heathrow's recent "Long-term hub capacity options" document.