I've been successful at trading in through RCI twice using my parents' timeshare week on Cape Cod. Their timeshare trades through the Weeks side of RCI vs the Points side. While I've heard that available trades into DVC tend to post to the Points side first, I don't think Points can set up an "Ongoing Search" (OGS) like you can in Weeks. The OGS is often key to getting a trade through RCI.
The first trade was into a 1-bedroom at Beach Club in June of 2011, soon after DVC switched to RCI as their exchange network. That trade was fairly easy to get (and cheap too, since they didn't have the trading history yet to get the "desireablity factor" in assigning the exchange power of the DVC resorts), apart from having to accept a 1-bedroom unit when we'd used a 2-bedroom to deposit.
The second trade we will actually check in to next week. We were able to trade into a 2-bedroom at Saratoga Springs. We set up the OGS back in mid-February and it sat until we got an exchange in mid-May (so 5 1/2 months out from checkin). The key is to be flexible on the resort choice. We were *hoping* for anything other than OKW or SSR, but we were fine if that's what we got.
If you're on Weeks, getting an OGS set up and running is key to getting the trade, since deposited weeks are matched in the order peoples' OGS'es were started. (Earlier start date means the closer to the front of the line)
And in Weeks you'll want to deposit your week as early as possible to maximize the trading power it's assigned.
If you're serious about trading in, I suggest looking into the TUG BBS forum
http://tugbbs.com/forums/index.php
Especially consider singing up for a 1-year paid membership (I think it's $15) which gives you access to the members-only Sightings part of the forum where people post exchanges and bulk deposits of popular resorts like the DVC properties, as well as the points required through RCI Points or the "Trading Power" required through RCI Weeks.
(I found out through that forum that my parents' timeshare would never have enough trading-power to snag a week in the peak seasons of summer or the holidays.)
Also note that DVC charges a $95 fee upon checkin to all RCI exchanges.
And DVC does not accept exchanges from timeshare properties within 50 miles of Orlando.
-Rob