One of the Ori's priar intends to set a beachhead on a planet controlled by the free Jaffa. Warned by a minor Goa'uld, former underling to Baal, SG1 try to figure a way to stop that.
Yet this demonstration of power start to show some weaknesses in the almighty Oris power. These all knowing powerfull entities seemed just to be unable to act very eficiency in our part of the Galaxy without establishing a base there.
This to state that they do need to rely on physical and highly technological means to achieve their goals. This fact alone is accrediting the theory of the false gods using tricks.
But we still have to admit that if we are to expect an Ori fleet this could be quite a challenge for the still weak "Homeworld security forces". The time would come (and i still bet on the mid-season clifhanger) when we will be granted a full demonstration of (military) power from their part.
One other element that seems important to me is the promise of ascension for those who served the Ori. That promise alone with the powers granted to the priars and other allies could be the key to the very essence of the Ori's power.
Needless to say that vala (Claudia Black's character) will be missed. At some point she may act as a serie regular. Avoiding strong connections with her former partner from Farscape was brilliant.
The return of Samantha Carter could be very problematic to the writers. Most of her links to the serie were cut since the end of last season (no more boyfriend, her father's dead, Jack is gone, special relationship with the replicators is no more. Looks like she will have to dig herself again a new place in the show appart from a pale version of Atlantis' McKay. A challenge to the writers and to Amanda Tapping.