I somewhat disagree with kundas1 - I think you will still need to look at a case or sleeve, probably for two reasons. First, carrying around an obviously cool machine could be a theft magnet, and secondly there are times you must walk, bus or fly to a meeting and you need a bag (in my case a shoulder strap case) for carrying the SP3, the chargers, and other stuff and still free up hands for other bags and meeting items.
Also consider looking at memory: I already bought a 128GB micro SDXC.
Also, depending on your needs and use patterns, consider a USB port extender (USB 3.0) to cover keyboards, mice, external HDDs, external DVD/BR RW, and perhaps even small projectors for ad hoc meetings and briefings.
And who's to say you aren't a doctor or EMT and you need the extra USB ports for electronic stethoscopes or EEG/EKG monitors (I really don't know if there is such a thing, but what's a Fit Bit but what I just said. And who knows what the future is for each industry.)