NIK Software have started to ship their HDR software - HDR Efex Pro. I have completed a quick side by side comparison of HDR Efex Pro and Photomatix Pro and I would say that NIK is comparing very well.
Out of the box NIK HDR Efex Pro manages very realistic and natural looking HDR renditions. There are a large number of pre-sets available to help the user 'play' with the effects possible. Each Pre-Set could be achieved through the adjustment sliders and clicking on a preset results in the sliders positioning themselves as necessary. This helps the user get to grips with the range of styles achievable quickly... although some of the pre-sets can result in some tacky looking renders :-)
HDR Efex Pro is a little slower than Photomatix on my machine (Mac Pro Quad Core 266 with 8GB RAM) but is usable...
I experimented with the software by re-visiting a recent HDR and attempting to re-render with HDR Efex Pro. The result looked better than my previous post production which was achieved after a significant amount of work in Photomatix. Here are the shots for reference, which do you prefer?