On the other hand, Chaosium can still sell the Alephtar Games books and PDFs. However, it seems they have disappeared from Chaosium's catalogue on their web shop.
Bottom line: if you're interested in TCE and see the book in a shop or on a web-site, do purchase it! It will become impossible once the current stock has been sold out.
Also, given the amount of work that it would involve, I have currently no plans whatsoever to re-write the book to make it compatible with another set of D100-based rules. I'm also way too busy with writing and playtesting Oriental Monsters & Magic.