This is a caliber that has really interested me, and I am in the process of deciding which rifle to buy chambered in this caliber as well...
The 6.5x284 Norma is an excellent long range caliber for both hunting and target shooting. A lot of the appeal for this caliber is the fact that the 6.5mm bullets (.264) have a high BC which aides in accuracy for long range shots.
There are a few good offerings in the 6.5 realm, such as: 260 Rem, .264 Win, Lazzeroni 6.71 Phantom (screaming fast), and others. But the 6.5x284 Norma seems to be the most popular of them.
One issue that arises with the 6.5x284 is barrel life. It is expected to have a life of about 1000 rounds, which isnt too impressive. (by "life" I mean accurate life)
Now that I have that out of the way; your question about using this as a deer rifle is a good one. This caliber is perfectly capable of taking deer sized game, but I am unsure of the effectiveness of this caliber on elk. I'm not saying it wouldnt work, but when compared to other calibers used on elk (like a .300 Win Mag), the bullet just doesnt have the same weight behind it for energy transfer. So, if you were to use this on elk, I personally feel that shot placement would be key.
Again, I'm not saying that this is not suitable for elk as I have no experience with shooting an elk with a 6.5x284, but I feel that there are better options.
As far as pros and cons are concerned: pros would be it is a pretty flat shooting caliber with a nice velocity at distance. Cons would be the barrel life mentioned earlier, also ammo availability isnt too great here in UT. Brass is kinda hard to find as well, and is generally very expensive. I saw some Hornady brass at Sportsmans Warehouse the other day for about $55 a box, and Cabelas had some Lapua brass for $120? So its not terribly cheap to shoot. Nosler does make a factory load, and so does Norma (these are the only ones I know of).