Yeah we understand the implications, but intentions are to be friendly in any environment -- even with other MooTools versions Oo.
This doesn't mean, though, that you have to follow the mindset. There will be a Array.install() (or perhaps a MooTools.install()) that will make 2.0 work like 1.3 -- that host objects (Array) are extended. So that you can [].slice(0, 4).each(). We'll write a blog article presenting the ideas and thorough examples to show that this gives us: *flexibility*, *robustness*, and in some cases* speed*. We've always believed to give you, the developer, all the power to make the decisions and you still have it to use generics or to use native extensions. Now, though, *Core builds can be used anywhere without worrying about breaking other people's code*. That's a huge win, imo.
