I agree with sparkman's conclusion at the end of that Scriptural waterfall...
Personally, I think there are many good reasons to honor the Sabbath still (the exact day doesn't really matter) both physiologically and relationally. In the US almost every business used to be closed on Sunday and in fact there were states where it was illegal to be open on a Sunday.
I don't think we should force people to honor the Sabbath by any means, however encouraging businesses to close one day would enable many workers to have time to consider that invitation to church from a believing friend that simply couldn't be accepted before due to work schedules.
There are some Christian-owned businesses that close on Sunday (Chick-Fil-A, many small local companies... ) and from what I've observed it actually boosts business because all those people who wanted to buy or shop on Sunday are reminded that they missed out. They should have gone the day before. Like Apple products, the limited availability of a service or good makes it even more valuable and desirable.
Anyway, that's all a rabbit trail, but as Believers under the New Covenant I agree that we are not required to follow the Sabbath, but to attempt to do so is a healthy and spiritually supportive choice.