Sometimes reviews take many months to complete. Sometimes due to myself, sometimes the product maker would rather the product wait. I do aim for completing a review every week, if not more, but at the same time, I don't rush stuff, and make sure I'm confident on what I am reporting.
I often get many products at once, saves the company on shipping at least. The Gigabyte Z77N-WiFi, they sent to me in September, and I got like 5 boards from Gigabyte within a week. All of those are done now.
I have four other products that have been waiting for months, a few memory kits, and a HTPC. HTPC was been waiting for other relevant hardware, and will be done very soon, two of those memory kits were bad, and at the same time, the PSU out of memory testing rig, that Antec, obviously had issues, and my memory testing platform is now dead and needs replacing...which means I got to re-bench a whole bunch of memory kits to get numbers for that one review.
Doing reviews isn't all fun and games, unfortunately.
When you get products before they hit retail, you tend to run into bugs here and there. Boards are one of the most problematic, evidenced by BIOS updates for board being put out many many months after a launch.
I have three more ASRock boards here, one is doing a 72-hour Burn-in testing right now, another will get started Friday, and in the meantime, I'm editing pictures and making graphs for next week's review. I usually have three or four reviews on the go at once. Oh, and I'm doing memory testing as well, well, at least, I will be working more on that later today.