Well... I took my camera into my dealer and they said that they would replace it... but I got their floor model and took a "dust shot" with it... and it was even _worse_ than my camera! So... no reason to replace (might just get one worse). They said they could send it in for cleaning... but it would be a month before I got it back. So, I told them I would use my Giottos Rocket Blower and see if it would do any good. I just got through cleaning the sensor with the rocket blower and thought I would share my results:
(all photos take using 24-70G at 70mm at f/22 focused near infinity on a piece of paper. Disregard the "yellowish splotch" it was some junk on the paper...)
First the "before" shot:
Next, the "after" shot:
This is after repeated (10+) mirror up cleaning sessions with the rocket blower. When I first took at look at the sensor I could visibly see the dust (mostly in the bottom left corner when looking at the sensor). I could see it getting blown away with the rocket blower. As you can see, there are still a few small spots... but they won't be visible at anything other than f/22 (where I don't shoot much). I could keep blowing, but it's just as likely that I will continue to blow around the dust instead of really getting it off. To get that last bit off I would need to either send it in or do a wet cleaning (which I'm NOT doing on a brand new $2100 piece of equipment. I understand that many people do... it's just not for me).
So the verdict? It is definitely _dust_. It is not oil (at least on my sensor) and it can be effectively dealt with in a "non-contact" way. I'm happy with the result and I'll just be diligent about blowing off my sensor every now and again. I hope that eventually it settles down a bit... but I can definitely live with this one "issue" for everything else that is awesome about this camera.
It is a huge relief to know that I can deal with this on my own and I don't need to send my camera anywhere....