I noticed in the first video we got of the band playing WPINOYB that Boz wasn't playing guitar, and I asked in that thread if anyone who was there knew what he was playing. A poster replied that he was playing a sort of small keyboard. Judging from Boz's motions in the video, it would appear that Boz is playing the piano glissandos, which is slightly perplexing. The video doesn't really show what part Gustavo is playing.
A few posters have also noted throughout the tour so far that Boz has been seemingly getting frustrated because the instrument in question appeared to be malfunctioning in the intro to WPINOYB.
However, none of this really makes sense if the instrument is being mic'd, which it appears to be.
He wouldn't be playing lapsteel, as there isn't one in the recording, and I can't really hear the sound of one in the live rendition.