The next version of HOL is just about ready for release. Look for it soon at all good theorem-proving systems outlets.
My choice of reviews above was mostly determined by how easy it was to find them. Some online newspapers are decidedly unfriendly when it comes to finding material. (Indeed, the (British) Times apparently now has an official policy forbidding links from elsewhere to anywhere on their site except the front page. If I could find anything useful on their site, I'd link to it just to thumb my nose at them.) The Guardian/Observer site is easy to use and preserves links to reviews that may not be in that day's edition. I fluked the Telegraph's review by using a search function that seemed to give me every article in their reviews section, but the LotR at position 10 on the list. The New York Times seems best of them all, with an online archive organised alphabetically just two clicks away from the front page. Now who'd have thought of that? (And these articles are available despite the NYT's usual policy of making things inaccessible after 2 weeks; hurray!)