Jeffery Dean Morgan wont get the part, he's much too small.
If it's a good script, and a good actor gets the part Lobo should be good. He translates to the screen like V for Vendetta, Watchman, and other more mature properties in the DCU.
The real problem DC has is translating their Superhero properties to screen. Other than Batman, and Superman a lot of the stuff in the general DCU just doesnt work well, because their heroes are iconic, and mature. Not as appealing to the youth as Marvel.