user196: Upgrading to 0.8 from 0.7 I noticed the old blk*.dat files were untouched, while it was created a new directory called blocks/.
I guess I can delete the old blk*.dat files? Is there something else I'm supposed to delete?

user53: Yes, if you don't plan on switching back to the old version you can delete the old blk*.dat files.
The final 0.8 release will include this little script to tidy your data directory:
https://github.com/bitcoin/bitcoin/blob/master/contrib/tidy_datadir.sh

196: <p>Upgrading to 0.8 from 0.7 I noticed the old <code>blk*.dat</code> files were untouched, while it was created a new directory called <code>blocks/</code>.</p>

<p>I guess I can delete the old <code>blk*.dat</code> files? Is there something else I'm supposed to delete?</p>
 53: <p>Yes, if you don't plan on switching back to the old version you can delete the old blk*.dat files.</p>

<p>The final 0.8 release will include this little script to tidy your data directory:
<a href="https://github.com/bitcoin/bitcoin/blob/master/contrib/tidy_datadir.sh" rel="nofollow">https://github.com/bitcoin/bitcoin/blob/master/contrib/tidy_datadir.sh</a></p>
