Quick post:
Will Dawn get a cameo? If so, what'll it be like?
Certainly an overly pearl-y episode would be great, but I don't want to get hopes up dangerously high unnecessarily. Seeing it strictly from a pragmatic and objective perspective, I'd expect there to be a cameo at some point either later in BW or in the eventual Champion's League (I've gone over this several times before, you know what I think will happen at the end of BW).
Then again, it's entirely possible that Dawn won't have a cameo at all, for one simple reason: only Misty has ever shown up in a SS episode and come back for more. Technically, SS001 and SS002 follow a similar pattern to SS024 and SS025, but May never showed up in an SS episode, and DID have a cameo. This may seem a bit convoluted, but Misty had unprecedented support, so she clearly got a large chunk of "extra" SS time, plus a cameo. May and Dawn, by the very nature of how they were brought into the show, lack this same support, and therefore don't necessarily get both a side episode, and a cameo.
There's another reason that a cameo might not happen, at least during BW. If BW's so fast-paced, taking up 2-3 episodes for a Dawn cameo doesn't make much sense. Not to mention, there's no clear reason for Dawn to show up in Unova, it would take some odd explanations of Unova's connection to the rest of the pokemon world, etc. etc.
That said, I do expect at least one more appearance by Dawn before Pokemon's approaching conclusion. So what happens during that episode? Simply put, more of the same. We probably won't get pearlshipping, just more of those great Ash/Dawn friendship moments we've gotten all along. Simply put, unless the anime writers decide to make one of the side-plots of the Champions League be Ash's awakened sense of "oh hey, girls", it's unlikely.
That said.... speculation time!!
When BW's all said and done, Ash almost certainly will have won. He has to beat his new Unova rival in the semi-finals or above (given pokemon anime logic), so he'll probably win the whole thing. That means he qualifies for the Champions League, which was set up so carefully in the Sinnoh Saga. What does that mean? Ash *has* to head back to Sinnoh to compete in the League. That not only makes a reappearance by Dawn almost ensured, but it also means that the pokemon anime is almost over. After all, the moment Ash becomes a Pokemon Champion, the main series is finally, finally, finally over. Given that, there are some unfinished bits of business. Technically, Ash is still in need of serious character development. He doesn't have a love interest, his father's still AWOL, etc. etc. etc. I would expect most of that to be handled during the Champion's League, if for no other reason than that they need to fill an entire season with what amounts to five six-on-six battles. I would also expect almost every major character to show up again. Maybe not Dento and Iris (since they technically are gym leaders in a far-off land), but Brock, Max, May, Misty, and Dawn would quite literally have to be there when Ash wins, with people like the Oaks, the families, the rivals, etc. all either in attendance or watching intently from home. That, plus the awakened love interest possibilities and the inevitable successes of May and Dawn in winning Grand Festivals (again, following Pokemon logic, neither can lose before the finals, and whoever has their GF shown will have to do better, which means win) means that the anime will be breaking a ton of new ground. There's no telling where this whole thing will end up.
Anyways, that wasn't actually a short post. Let me know what you think! I gotta hit the sack, so g'night!