Every time I play with Arduino I wish it was smaller. Proto boards have been the same size forever.
Arduino boards should be postage-stamp size or smaller. Yet remain compatible with proto boards by virtue of some new, tiny connectors, perhaps 1/4th or even 1/8th the size of the current (0.1 inch) monsters, that fan out to fit the old stuff. Via ribbon, or whatever ... Then, once you build something you simply wire it together more permanently and stuff it in a tiny box where it belongs. Proto becomes product.
The electronic world keeps getting smaller, while supposedly tiny Ardiuno appears larger every year in comparison.