I for one, am not really anticipating any new music at the opening in Columbus. I will be kinda shocked if they do. On top of not releasing any new promotional band shots for this tour -- which I'd imagine would've been also released to promote the new single(s) -- they haven't even been bothered to name this tour outing.
They're too busy semi-promoting a fan made tour poster contest on Fleetwood Mac's FB page, as if that should include & appease us
. And since this is uncharted territory for the band (sticking a couple new songs for download on the Internet) maybe WB, or whoever is supposably releasing these new songs, is unsure how to market them.
I feel as though these songs will go the way of that comprehensive FM re-release with unreleased footage (probably the Rumours deluxe box shelved) that was highly talked about in every press release following the annoucement of FM's 09' "Unleased Tour", that was never released or brought up again once the tour started.
Perhaps they have rehearsed the songs, and they didn't transfer well to the stage as they sounded in Lindsey's home studio?!?
Or the non-cynical view, WB & FM are soooo impressed with these three new recordings, they have decided to see how things go on the 1st leg of the tour, and possibly record some more songs on the road for a new FM record late summer/early fall.
This tour is simply a cash grab
And I've really had the impression that Stevie is really not interested in recording with FM again, unless Christine is involved, and that is not going to happen! Stevie probably met with the band in November at Lindsey's home -- threw her vocals on Lindsey's 2 tracks & dug out "Without You" to appaise Lindsey and have the start of this FM outing go off with her appearing to be compromising, have things within the Band go off without a hitch & any tensions. But maybe she never intended that these would really be released. Well, maybe "Without You" for a BN re-issue later.
Also it's entirely possible that Lindsey is stewing that Stevie (solo) has been in the limelight the last 2 months fronting The Sound City players & playing her new song wherever she seemed to have the chance. And then more recently over the last 2-3 weeks (since SXSW) we've seen a lot of Stevie solo press about the North American theatrical release of "In Your Dreams" movie documentary ("the best year of her life".) 
Could there be "Trouble in Shangri-la"? Or as I suspect - Stevie is just calling all the shots.