I think it's great with the main page and the feed. It took a bit of getting used to and I didn't like it at first but it's grown on me and I really like the new setup.
Funny you should mention this bro' and for several reasons:
Back in the day rule 15 was an attempt to achieve something similar but of course it would've been too-draconian to ask members to prepend sale statuses as opposed to simply mentioning them in ad titles. The tags ensure said statuses are abundantly-clear.
The colour coding uses shades of green to indicate the various flavours of availability and different colours altogether for seeking, sold and withdrawn items, making it easy to scan for what you want.
It's interesting that even 'though nothing is stipulated, 99% of ads already employ the tags.