Blur would be amazing.  I still think if this thing's at Merriweather, the headliners won't be bigger than Blink/Weezer.  Neil Young, Metallica and co could easily sell out MPP on their own, so the likelihood of them playing a small festival there is low.
Blur however, could be a decent choice.  This isn't the UK, after all, so Blur isn't exactly the biggest deal in the world, but it could still be big enough to be a Merriweather show on tis own.
If they do end up playing, I'd strongly lean towards going.