Once we have confirmed number lines, the targets melt away. This is a "significant" breakout in the dollar. I'll give anyone a free cookie if they can tell me what is the "likely" driver for the dollars strength and why it's going to get significantly stronger because of this driver. It's a pretty big cookie too. Not like those small ones I use to give out before.
From my perspective US economy and dollar simply stabilized and it's more weakness of others than dollar's strength. EUR is 57% of the basket and in my opinion it really looks horrible. Interest rates are so low EUR basically can be called carry currency now (which is negative for it during risk on). Privilege to deposit money in ECB now cost money to banks (negative interest rate)! And Yields are so low its hard to find a reason to park capital to some Italy bonds when US treasuries pays the same or more. Unemployment in Spain is freaking 20%! France, Italy ~11%. This creates expectations that EUR should drop further which make carry trade and US markets over Europe even more attractive which creates even more capital flight from Europe which make carry more attractive...

In my opinion ECB monetary policy can't do much more because new money created with QE probably would end up invested in Germany anyway. Without some reforms to remove inefficient socialism/to lower taxes/to lax regulations in Spain/Italy/France new money wont help with new investments and jobs creation in those countries. Maybe that's why ECB started this experiment with negative rates. On top of that there is this situation with Russia. US markets pretty much safe even in unlikely scenario of big war. And strict sanctions and economic warfare is really hurting some European companies which on top of general economic weakness creates even more capital flight from Europe stock markets. And it probably goes to US (thus USD up). So it is likely that EUR just have to correct itself to make EU more competitive.
JPY is ~14% of the basket and I guess they just have to do something about their huge debt and economic stagnation. However because GDP failed to grow as expected all this stimulus is probably viewed as inflationary by investors. And it probably is. It makes sense - inflate currency, stabilize, raise taxes, inflate currency a bit more, raise more taxes etc (which I think is again on the table at least I've read about more tax raises). Limit on yen weakness is probably set only by oil prices since Japan buys energy from outside and yen too weak would cause trouble there. JPY is also carry currency. Other than that I don't know much about Japan.
GBP - I have no idea. Maybe Europe is dragging it down. Maybe fear of Scotland referendum. Maybe it just overextended and market expected much more from UK economy. However price action is extremely weak maybe there is something more to it.
And US economy now looks pretty healthy QE 3 is ending, rate hikes are expected soon, shale revolution makes US more independent (huge for economy) and that could make dollar again real petrodollar

Oil prices getting low - dollar strong. Dollar strong - gold cheap. And probably it again starts some kind of cycle of capital reallocation which fuels breakout.
That's my humble opinion about what's going on, of course it's hard to know for sure. I am really interested what others think about that.