The latest annoyance with RIA (Rich Interactive Applications) these days (not wide-spread thankfully) is how they aren't really suitable for search engine's such as Google.
There's a reason for this and it's simply put, they aren't web pages. They aren't documents, and furthermore they aren't worth indexing. That being said the data that they connect to, is all of this and above.
You see, the confusion kind of sits around how they are deployed, in that we typically gain access to a RIA via a browser right? In this context, then by rule of thumb they should be indexable and search able by our favorite search engines - after all, it's the browser paradigm right?
Actually no, the browser is simply the payload first and foremost, it's your footprint to gaining access to the RIA in question. In some cases (AJAX/Silverlight) the RIA makes use of HTML or XAML, so surely that means it's crossed the boundaries of being part of a graphical element and into indexable data? Wrong - this is just us using the subset language we've been dealt to produce layout, or positioned elements on screen and although the code is somewhat transparent, assume it was just a ball of .DLL.
How does one strike a balance then? Take a look at the New York Times Reader built in WPF, this by far is a perfect example of a RIA. It basically connects to a remote location, downloads the latest news articles, saves them as XML packets on a person's hard drive and then is indexed by Windows Vista. If you were to go to your Start -> Start Search, type in say "IRAQ" you'd get all news articles relating to IRAQ. If you then click on the article in question, up comes the story inside the WPF Reader in full view and within context.
This is what the next evolution in RIA Designers/Developers will have to think about, how does one produce a high-end user experience to end users whilst allowing them to hunt for information of interest via search engines. I think the WPF Reader methodology is one of many correct ones to use, and this is realistically where deep linking plays a role.
This all being said, we now need more RIA Architects, as the developer & designer base can do the between bits, but it's important to have an architect whom can see the overall vision end to end.
Here's some good reading on this, and interesting thought process around these: