Here's the truth about Beowufl. The poem sucks. Even if it's in a language you can read, it still sucks. When I was in college I read some of the great historical works of the past in Europe, some in translations, some in the original language (if I knew it), and Beowulf was by far the least interesting "classic" work I have ever read. The fact that Tolkien cared about it means nothing to me nor most people. Want proof that while this is of interest to the Tolkien fan boys, nobody else cares? Some years ago Robert Zemeckis, who is a directory I generally like, decided that everybody was just dying to see an adaptation of the film. It made about 60% of what it cost to make it. The truth is, most people don't care. The story sucks and few are interested in it.
And exactly how much, fan boys, do you think his translation is going to bring to the table any way? If it's vastly different than what came before it, then somebody blew it. Either Tolkien's is different because the people before him were really bad at translation and botched it, his is different because he is taking massive liberties with his translation and making assumptions that the original text may not actually support, or it's going to be barely different at all because there's just not that much difference between proper translations. I've done some translation work in my day and if done properly, there just shouldn't be all that much variation between different translations. I suppose Tolkien might use a word order better suited for modern readers or use less complicated words that convey the same meaning as previous translations, and I'd praise him for that, but such things should really be fairly minor versus previous translations.