Yup, that's correct! Version 0.8 will playable in Java AND you can download different versions to suit your machine!
It will work like this:
v0.8D
Release Date: 5th February 2008
This version is for players with a decent Windows PC with a Direct X9 graphics card. This is the recommended version of POLR to play as the game is built originally like this and uses the graphics to process data and render graphics (meaning smoother gameplay)

v0.8ND
Release Date: 5th February 2008
The ND (non-DirectX) version is for Windows Users with an older PC. It doesn't require any graphics card as it draws using Windows software.

v0.8J
Release Date: 8th February 2008
The J version is the Java version for those who use Linux or Mac (it can also be used in Windows if the other versions cause problems). It will have a slightly different layout due to it being run from a virtual environment (which is how Java works) but it'll still have the same game experience. I'm still unsure if it'll be compilied as an applet or as a web start application (either way, Offline Mode won't work entirely offline).
If I purchase the developer edition of MM2 in the future, it is possible that future versions of the J build will be available as an downloadable game (meaning offline mode would be entirely offline), I am still undecided at the moment as to purchase it or not.

I've also attached a poll to see which most people will use