Sounds exactly like the 5 foot step rule. But, why use it? Players need a reason.
The shift is like the 5' step once it has grown up and gotten a degree.
By making it a move action, you can shift and then move (by cashing in your standard action for a second move), unlike in 3e D&D (not sure about Conan). Also, tons of 4e monsters and powers have "shift 2 squares" or more abilities. But like I said in my post above, with full attacks (which 4e lacks), spending your move action for anything has a huge cost attached.
That's why I suggested possibly employing feats for this, expanding on the 5' step in various ways. You could have things like:
Expert Step- When you take a 5' step, you may move an extra 5' without provoking attacks of opportunity.
Battlefield Step- When you take a 5' step and are adjacent to an enemy, you may move to any space adjacent to that enemy without provoking.
Mighty Step- When you take a 5' step, you may make a Bull Rush attempt against one enemy adjacent to your starting square. You can only push the enemy 5' with this bull rush.
Quick Step- At the start of your turn, you may take a 5' step even if you will move later in the round.
Tactical Distraction- Whenever an ally within 30' triggers an AoO, you may take a 5' step as an immediate action.
If you don't want to make them feats- as this costs characters other options to employ them- you could make them combat maneuvers that you gain access to with sufficient BAB. (Note that I didn't really worry about what prereqs would be appropriate above; obviously some of those ideas are better than others.) Making them all free like that also would definitely encourage a more mobile sort of combat. On reflection, that's probably a better path to get what you're after.
One caveat is that you might need to look at Tumble if you do this, I don't know if it is different in Conan.
I have to say, whatever its flaws, 4e gets dynamic combat pretty well right. You can probably find a bunch of cool ideas if you know someone familiar with it who you can mine for ideas.