The main question is whether you've done any programming in the past since that may be the main effort. I would suspect that if you had not, you could get by but not necessarily do well. You indicate that you didn't have any programming experience, so this is where you are going to have most problems and spend most of your time. Java would not necessarily be faster or slower to learn than other similar languages.
Sun's Java tutorials are great, but unfortunately programming is one of the things where practice is necessary, and that depends on your free time. It's also necessary to stop and practice frequently rather than after reading half a book. If you devoted 10 weeks full time to it - yes, it's quite doable for some people. After all, college students become passable developers in one academic year where they take other unrelated courses.
I would focus on figuring out Java fully first without trying for J2ME. Then you can make the switch.
In addition, realize that there's a big difference between the language and the standard library. The important thing is to learn the language. There are certain standard library calls that everyone uses and are critical to learn, but they're not part of the language. However, you'll never really know the entire library (Though you'll learn from exprience). It's more important to learn how to find the functionality that you're looking for then to know exactly what it is or where to find it. The important thing is to avoid reinventing the wheel.
Also, realize that you may only be a passable developer at the end. Experience takes time and often can't be hastened.
In addition, even if you learn to program you will miss some of the critical general CS knowledge like data structures and algorithms. Programming books rarely teach that, you will have to learn that yourself (see, for example, the TopCoder tutorials).