I think many are missing the subtlety of this particular angle if the suit. This filing is specifically aimed at:
ADA implications if the bill (non standard magazines)
Interstate commerce (banned rifles being a key income source for local FFL's)
And a direct association of "common use" firearms as defined in Heller.
As others have mentioned, this is not the primary 2A suit, that one is sure to follow. Keep your shorts on, I predict within two months you'll need a spreadsheet to follow all of the different filings.
TxAggie, it also had a very interesting slant to it, to use the phrase "In the home" so that it didn't invoke the finer points of Heller also supporting outside the home.
This is clearly a dagger straight-to-the-heart approach on this. No reason to include extraneous info, they'll just use that for diversion tactics.
I especially liked the fact that preference for law enforcement over say retired veterans or "regular" citizens was a violation of equal protection under the 14th.
Take away the exclusions for law enforcement and there will be an uproar from them. They know extended magazines are critical for defense.