Actually Force orb is considerably weaker. The damage to secondary targets is under the "Hit" portion, therefore if you miss the primary target there is no secondary attacks whatsoever.Hmmm... well, my DM took a good look at Grasping Shadows in comparison to other 1st level Encounter powers (especially Burning Hands and Force Orb) and thought it was on par.
Regardless, I'm going to suggest lowering damage to 2d6 to balance it between Burnings Hands and Force Orb damage. Force Orb is essentially the same... except it does less damage to secondary targets and has no additional effects (slow, weaken, etc.). Grasping Shadows does 2d8 to all in the burst area AND slows them... and it targets Will, generally a low monster defense. It is also a zone of sorts in that it remains in play and can damage and slow other creatures entering it.
Thanks for the response, Larrik! And a special thanks for clarifying my second question. Good example with Cleave and I ought to have thought of that, having played a Fighter before this Wizard.
We had a wizard with force orb and when AP came out I (thats right, me...the DM) advised him to change over to grasping shadows. Truth was force orb had proven to be a real turkey of a power, and it was my feeling that graspong shadows is about where a wizard should be.
My position is not that grasping shadows in OP vs other wizard L1 encounter powers, its that most wizard powers were UP compared to other classes.