Nikon J1, most useful lenses/accessories?

I have 2 cameras, my Canon 20D and a cheap point and shoot that broke recently. I love my 20D, even though it's probably really outdated now. It's also a pain to lug around to every situation I would want to take pictures, and I haven't ever been able to afford the 2 lenses I Really want for it (both over $1000). The point and shoot was more convenient, but the photo quality was really bad in any indoors/low light situation. I found a great deal on a refurbished Nikon J1 with the 10-30mm lens. I have been looking at them for a while, since it seems like a reasonable compromise between my good camera and another junker point and shoot camera.

Once I get it, I want to go through and learn all the features like I did when I got my Canon. After I have a good handle on it, I'm pretty sure I want to order the 30-100mm lens and a filter set (I have a bunch of cokin special effect filters for my Canon, and have a lot of fun with them). I'm not sure what other lenses or accessories would actually be useful vs.becoming dust collectors? Any suggestions or comments on what's worked for you? Also does anyone actually know what style mount the J1 has? Is it unique to the J-series?

The mount is called a CX mount, and it is unique to the Nikon 1 series. The J, S, and V series all use the same lenses.

I have a Nikon V1, and the most useful accessory for me is the FT-1 adapter, which allows using full sized Nikon f-mount (DSLR) lenses on the Nikon 1 series.

I have a Nikon AF-S 70-300mm and on the Nikon V1, it appears like a 192~810mm lens; great for those long shots.

I also have the 30-110mm lens and the 10mm pancake lens. The pancake lens is useful if you want a smaller package - but still not quite pocket sized.

Maybe one of the first things I'd buy is an adapter to use the Canon filters on the J1's lenses.