To answer your questions
1 and 2. Its not at all difficult to get HSMP. You have to get all your documents in place and apply directly to the HSMP office in the UK. There is no need to go through consultants. It takes about 4 to 5 weeks (normally) to get a decision on your application. It might take more time if there is any difficulty in your case(where the Home office(UK) are not happy with your documents and carry out further checks). you can get more details on this web page
3. No, you dont need to have an offer before applying to HSMP. Infact you dont need an offer to come to UK too(on HSMP). But it always helps to know your marking in the UK and mention its details in the application
4. The J2EE market is fairly positive for the right candidates. But as the year end approches, number of jobs on the market will fall. The best time would be Feb-March
5. Dependents are eligeble to work when the spouse is on HSMP
6. Coming to UK on HSMP is a 2 stage process. Getting the HSMP approval and getting the Entry Clearance (read visa). Once you have the HSMP approved, Entry clearalce can be given initially UPTO a maximum of 2 years. You would need to get the HSMP extended at the end of 2 years. According to the current process, you will be issued a further 3 year's visa. At the end of 5 years (2+3), you can apply for permnent residency. UK is moving towards a points based immigration system from early next year.
Things could change .
Hope this hepls
[ October 15, 2007: Message edited by: badari gururaj ]