I hope you are right, but I feel its unlikely. If they release a retina iMac with haswell - a lot of people will wait to buy, because they know broadwell is around the corner.
But who knows, Im no oracle, so I´ll keep my hopes up
What else can Apple do to make the next iMac seem more than a "refresh?" A higher resolution display is one. That will have to be coupled with a 900-series GPU, which are becoming available. I suppose they could also make changes to the outer design, such as making the stand height-adjustable (which I would welcome). The iMac is already "thin," and they're certainly not going to add optical drives back in.
So Apple is already very close to having what they need for a decent update, minus Broadwell. But I wonder if expectations of what Broadwell will do are a bit high, especially for iMacs. They'll be more efficient, with a lower TDP, but the iMac with Haswell already does quite well in heat dissipation, especially compared to iMacs prior to the late 2012 update. I'm also skeptical that the rumored 40% boost in integrated graphics performance will make that much of a difference for the iMac.
The only question is whether Broadwell's improved TDP will be
required to offset any of the other internal changes. If so, we'll probably have to wait until around mid-year. But if not, Apple could release an upgraded iMac soon and then introduce Broadwell as a refresh when it's available.