The people on this thread arguing that we shouldn't change over have the same delusion as mainstream economists. They think people are perfectly rational. That is, people act as perfectly rational economic actors that realize 1 BTC = 1000 mBTC and hence a change like that won't matter.

If you study behavioral economics at all, however, you know that people are not perfectly rational. In fact, they're very often irrational. This is why people complain about how expensive bitcoin is. This is why altcoins have been going up relative to bitcoins as more investors come in. .03 BTC sounds like a miniscule amount. 30 mBTC does not and a lot of people make economic decisions based on how something "sounds" than how something IS.

That is why we need this change to mBTC. The whole argument that there is no need for a silver to bitcoin's gold comes from divisibility. It's a largely useless divisibility with BTC because people don't transact in numbers that small. Rationally, .003 BTC is the same as 3 mBTC and both buy about a cup of coffee. The former is simply too difficult to relate to while the latter is easy. It's not easy to grasp the difference between .0003 BTC (30 cents) and .003 (3 dollars). That sort of distinction is obviously huge for commerce as that sort of denomination is much easier to scale relatively.

Yes, eventually, we'll have to get to uBTC and possibly even Satoshis. But changing over the pricing structure isn't a bad thing. It's meant to HELP people to relate prices better. This is why it's important and this is why every exchange and store needs to rethink how they label bitcoin prices.