http://pastie.org/private/krcevozww61drdeza13e3a will be a lot of use. Also remember it's a good idea to rename your views. There is a rake task somewhere for this at http://www.slashdotdash.net/articles/2007/12/03/rails-2-upgrade-notes which works if you use subversion (remove the svn calls if you don't use svn)
Also note that is you want to take advantage of most of the improvements and changes in Rails 2.0.* you need to be designing your app structure in a mostly restful manner. If you are creating weirdly names singular and plural resources when the opposite is expected instead of using the generators you will find your life quickly becoming hell.
Rest has won the battle, bucking the horse now will only cause you undue pain. :)
Balaji you may find a peepcode book on Rails2 a good read if you are planning for a migration to 2.0 . I am pasting a the purchase link here for you.
Remember pagination was taken out. The will_paginate plugin is now the accept way to do this.
Also session security has been enhanced so you may want to generate a new rails app and then take the session code and move it into the older codebase.
Can we just list out points/actions to be done/taken care to ensure a smooth transition while upgrading rails version to 2. So that this can be used as a checklist for developers.
Also info about good tutorial for rails 2 depricated functions ... etc ?
Few slideshow/tutorails i came across, http://www.slideshare.net/brynary/whats-new-in-rails-2/ http://railscasts.com/tags/17