CR is gone as a static "level" of monster, but a far older measure of creature power is returning: XP.
Re-read the dungeon design article. Encounter Level (EL) used to be a static number (5 for example) but now its an XP amount (5000 xp). Lets say a good, typical award for an encounter for 5th level PCs is 5,000 xp. (= to EL 5 in 3.5). What is the difference?
1.) It will be easier to mix and match monsters on the fly. Quick, what is the EL of four orcs (CR 1/2), an ogre (CR 3) and his pet dire wolf (3)? Betcha can't tell me without looking at the chart or just giving me a base-guess (answer: roughly EL 5-6). However, if orcs are worth 250 xp, an ogre with 2000 xp and a dire wolf worth 2000 xp, you can tell me easily (4*250) + (2*2000) = 5000, or a 5th level challenge.
2.) It will be easier to divvy up the Xp at the end of an encounter/session. No clunky charts, or doing XP once for each member of the group one level higher/lower than the others. 5,000 xp, 4 PCs. 1250 Per PC. You could actually do it after every encounter, if you so chose to.
3.) XP rewards tailoring the encounter can be used for non-combat just as easily. Navigating a river of lava might be 1000 xp. Convincing the duke to help you (social interaction) is worth 3,000 xp. Disarming the scythe trap is worth 500 xp. By assigning xp amounts to social encounters, traps and hazards, you can make them more dynamic, more interesting, and more rewarding. (It can also be used to integrate them into combat encounters. Imagine trying to convince a fire-salamandar lord to let you pass while fending off fire-snakes over a river of lava! That is a serious encounter!)
4.) It STILL acts as a buffer to what monsters are considered an appropriate challenge. For example, if my 5th level party is going to face a 5,000 xp encounter, the 20,000 xp beholder is NOT a viable choice. Unlike CR, which was supposed to fluctuate somewhat (+/- 4, by the DMG), the xp cap acts as a better cut-off point. (A balanced encounter can be lots of different combinations of monsters and such, as long as it is @ 5,000 when you're done). Sure, nothings stopping you from using that beholder, but you know that a.) The reward is far more than any 5th level PC should get) and b.) its 4x what a 5th level PC should face.
5.) Finally, there is no longer a "monster is pointless" cutoff: an orc is still 250 xp. At first level, thats a lot, at 20th, its barely a blip. However, there is no "you've outgrown Orc XP" level any longer.
I'm liking this system moe than the CR system, but thats because as much as I liked CR, It did feel artificially constraining. This system retains some of the best elements, but allows for a more old-school feeling of mixing and dynamics.