Personally, I see that commandment as ceremonial and therefore really doesn't apply anymore, but that's not a common view (and not a Lutheran one).
I think that rest (and often that's far more emotional than physical now) is a very good thing.... but whether it needs to be for 24 straight hours (and no other) or particularly on Saturday - that I'm not a bit legalistic about. To ME, Saturday is often a busy day but with personal and family and fun stuff - so it is in a sense restful in that it's not my "job" (which can be pretty stressful). To ME, Sunday is a day for worship, family and some kicking back.
Personally, I don't believe that public worship is REQUIRED (just a really good idea) - and certainly not on any specific day of the week. Sunday makes a LOT of sense to me since Christian worship is always in light of Easter, thus the saying "Every Sunday is a little Easter, every worship is an Easter celebration."
Blessings!
- Josiah