I suggest adding an entry in Special:Preferences (user profile tab) similar to "E-mail me when my user talk page is changed". A new entry called "E-mail me when a page or category on my watchlist is being discussed for deletion."
I also suggest separate special entries on the watchlist that are easy to see via a bolded font, and a different color such as red or green. The special entry should only disappear after the deletion/renaming discussion or deletion review has finished. The special entry is separate from the regular entry for the last edit to the page or category.
Many complaints and much disillusion with Wikipedia occurs because people aren't clearly notified of deletion and renaming discussions of pages and categories. Renaming is in reference to categories only. Renaming is included here because category deletion usually occurs in concert with renaming. See:
For more info see this discussion page:
http://en.wikipedia.org/wiki/Wikipedia_talk:Categories_for_discussion - go to the section titled something like "Add requirement that category creators be notified". The discussion is currently ongoing and has expanded beyond just category creators to Wikiprojects, anybody who has watchlisted the page or category, and more. The discussion will eventually be found in the talk archives by the time some people read this bug thread. There seems to be consensus for some kind of clearer notification, but the problem is the large amount of work involved in notifying all the people watchlisting an article or category. Also, some people do not scan their watchlists every day or even every week. Edit summaries get missed due to later edits, cryptic edit summaries, or lack of thorough scans of large watchlists.