ModularPhones.co is still available to reg so doesn't look like people are jumping at the chance to own a .co in this niche. But still, would hate to be the one that says 'drop it' only for someone to make a profit on it further down the line...
Modular tech is an interesting one, what with the miniaturisation of technology on the whole. Reckon the next 12 months will be most telling in terms of companies investing and developing modular gadgets. Lego for grown ups...