Seems there's a lot of good new preamps about right now - the darkglass vintage deluxe the mxr m81 and, albeit a little different, the jhs color box are the ones that sound particularly promising to me.
The vmt deluxe sounds very exciting - not personally a fan of the vmt but with the eq could produce something interesting. The m81 is the m80 without the distortion and with sweepable mids, and a smaller footprint - sounds ideal for those seeking tone-shaping only. The color box seems capable of a bit of everything, though having listened to all the clips I prefer the cleaner sounds.
Don't know how I'm ever going to decide on a preamp now