If you haven’t yet heard, the following is a card rumored to be in Rise of the Eldrazi (unconfirmed; rarity unknown):
What makes this better than Cancel?
1) You can play it on turn 2.
2) You can play it late-game effectively as “Counterspell.”
In the first example, playing it on turn 2, you’re now behind; yes, you traded with their 2- or 3-drop, but now on turn 3 you need another counter to deal with their 3- or 4-drop, which is likely better than whatever card they played on turn 2. So do you play ANOTHER Deprive (assuming you have it)?
Honestly, I don’t even think this is worth playing on turn 2.
Let’s say you don’t play it on turn 2, but you hit your first three land drops and then want to counter something. What’s better in this situation? Cancel or Deprive? Cancel, obviously. Deprive leaves you with 1 mana open which will likely go unused. In the meantime, now you’re set back a turn and you’ve likely wasted any advantage that Deprive provided you.
So, okay, late game then. This is where Deprive is at its strongest. But when is it really going to be that much better than Cancel? Really only when you’re returning something like Halimar Depths, as far as I can tell. It allows you to tap all but 2 land, unlike Cancel, but is that really such a huge deal?
For the moment, I’m going to predict that if Deprive sees play in Standard decks akin to UW Chapin Control, it’s going to be in numbers less than 4, as its early game drawback just seems like too much for a deck whose strengths lie in getting to Stage 3. However, I can see it being a possible staple in some sort of UG deck that can recover from the tempo loss using the myriad of mana accelerants available in Standard.