Let's be clear: Non-SuperDish systems can use the new DPP Twin LNBF, *without* the DPP44 switch. (Legacy tuners may prefer the DPP44 due to no longer needing a DishPro adapter, but even then you'll need DishPro LNBFs.) SuperDish systems will require the DPP44 in place of the DP34 that traditionally comes with SuperDish. Either the DPP Twin LNBF *or* the DPP44 will put two tuner feeds on one DishPro-compatible coax drop for your dual-tuner receiver.
The DPP *Separator*, which breaks out the two separate tuner feeds in that one drop, is *always* required.