Marriotts are your best options - you have the Tyson's Corner Marriott, a Courtyard Tysons Corner, and the Ritz Carlton. There's also another hotel - which is right next to the Courtyard - it used to be Holiday Inn, but it may have been rebranded to something else, I can't recall - either that, or it got redone to be a much nicer Holiday Inn. There's also a Westin which used to be an Embassy Suites on the other side of the Beltway. It's technically walking distance, but I wouldn't walk it with any sort of bags. I don't believe any have shuttles. The best bet for walking distance is the Ritz or the Tysons Marriott.