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It's the first time I see that an user deletes the OS X kernel by mistake. Be more careful the next time.
As you made a Time Machine backup before, it's easy to recover all your files:
1. Insert the Mac OS X Leopard DVD and press the C key while your computer is starting to start from the DVD.
2. After the disc has started, go to Utilities menu, choose the option to restore the backup and follow the steps
The problem is that Time Machine backups aren't bootable. However, you can try using an external disc drive, but I don't guarantee that it's going to work