Lets deal with the 4pc first, as its easier.
Assassination: The Vendetta boost is 1.5x times stronger than the Glyph, which (for me) is worth 320 DPS; hence, the set bonus is worth around 480 DPS.
Combat: 60% of Glyph of AR, which, for the Combat rogue in my guild, is showing as 897 DPS; hence, the set bonus is worth around 540 DPS.
Subtlety: Identical to the Glyph; speccing myself Sub, I show it as worth around 330 DPS.
Since 1 EP provides a bit more than 1 DPS, we're probably talking something around 400 EP for Combat and Assassination, and more like 250-300 for Subtlety. This is pretty good - similar to the T12 4/5pc.
The 2pc reduces the energy cost of abilities by 20% while active; this effectively gives us 25% more energy to spend (1 / (1-.2) = 1.25). It has 20% uptime, so thus gives us about 5% more energy to spend (more, if you pool to optimize the buff - but lets ignore that for the moment). Hence, the set bonus is equivalent to roughly a 5% energy regen increase.
Glyph of Tricks - which is conveniently scored by ShadowCraft - is .5 energy per second; 5% will be between .7 and .9 energy per second, depending on spec. Working out some napkinmath, we find that the set bonus is worth something like 700 DPS - as in, really really good. Perhaps too good. Particularly since you can improve on that with good energy management.
I also feel the need to reiterate my dislike for Tricks-linked set bonuses. I won't repeat the whole argument - you can find it
here if you're curious - but I do hope they replace the 2pc with something better before the patch is released.