I just did this. Unless you're targeting something really high end with a lot of 4K and gaming, 4600 is more than enough to handle typical HTPC duties.
I'd certainly look at Kaveri today instead of Haswell for HTPC if I was doing it all over again though.
I've gone integrated on my last two HTPC builds.. my current one is going on 5 years old now.. and have been considering a jump... ironically it's by far the slowest computer in my apartment, and the one I use the most.
Something like this really appeals to me.. I'd been keeping an eye on the F2 line, and will probably go that way, or maybe NUC for my next HTPC, it just feels like the NUC options are just a little under powered.
The Gigabyte BRIX has an Iris Pro-equipped model if that's something you want.
In my case I wanted in-box optical and tv tuner, which eliminates the NUC stuff. There are a handful of right-sized 'htpc' mini-itx cases that enable this and a whole bunch of nice mini-itx boards now.
I'd certainly look at Kaveri today instead of Haswell for HTPC if I was doing it all over again though.