I don't think I have the post count yet to allow me to post links, but just search for "Blueholme" on DTRPG or RPGNow and you'll find it right away. Googling "Blueholme" and "Dreamscape Design" will also take you to my website with the links.
Yes, there are some small differences - for example, movement rates. Movement rates came into OD&D via Chainmail, which had two movement actions per turn. Holmes got it right for player characters by doubling the old movement rates to give the correct movement-per-turn, but the monsters didn't - with the unfortunate result that monsters moved half as fast as characters. This was actually exacerbated in later editions, which took the half movement rates and applied them to characters as well as monsters. If you've ever wondered why everyone in D&D moves so slowly, this is why!
Another error in Holmes was the use of weapon speed without counterbalances like differential damage or reach. If all weapons do 1d6 damage but daggers get to attack twice a round while heavy weapons like pole arms attack every other round - well, everyone uses daggers. This rule was simply dropped from the Prentice Rules, although Compleat will include an optional rule for weapon speed with differential damage.
But, on the whole, the point of BLUEHOLME is to cleave as closely as possible to the original mechanics and intent of the Blue Book, so you won't find any major changes that are not related to either errata or clarification. Anyway, it's free, so go and download a copy!
