The KS legislature recently passed, with virtually no media attention, a bill lowering the compulsory education age to 6 from 7 and mandating half-day Kindergarten before entering first grade. This is quite similar to legislature that was opposed by the homeschooling community and defeated last year. You can read some information about it here. However, this particular bill was amended so that parents could request exemption from the requirement.
Honestly, I'm not too concerned about this bill. If you are opposed to any compulsory education or government involvement in education then I see why you might be opposed to it. The arguments at the HSLDA site, that beginning academics earlier doesn't show any benefits and has definite drawbacks compared to delaying them, is quite true but I honestly don't think it will be affected by this bill. Kindergartens and first grades in KS are heavily academic, at least those in my area are. I don't know of any non-homeschooled children who don't begin kindergarten at age 6 and I also don't know of any who skip kindergarten and enter school at the first grade level. This bill is truly only bringing the law into conformance with practice.
Homeschooling families will need to register as private schools a year earlier, and it would be advised to begin keeping more careful records at that time as well. There are no reporting requirements at all in KS, so the bill will have less impact.