<p>My company has been working on a Flex dashboard that displays realtime financial information. It will be deployed over a corporate WAN to perhaps a few dozen users. </p>

<p>This is our first Flex project, and while development has been very pleasant, we're a little concerned about what production issues might come up (users not having the right Flash player installed, long download times,BlazeDS performance, etc). </p>

<p>Our stack is RDBMS/Spring/BlazeDS (remoting and messaging)/Flex. </p>

<p>Does anyone with experience deploying a commercial Flex app have any words of advice?</p>

Your biggest problems are likely to be:
your users not having the correct version of the flash player
your users having locked-down desktops and either not being able to download the right version of the player or not being allowed to use the player at all
download speeds of the swf if you have a big app
intermittent loss of connection to your back-end due to either bugs in your code or unavailable network connection
restrictive browser policies
None of these are insurmountable, but you are likely to encounter all of them in the first few months.
I am presuming that you have tested your app for performance under reasonable load and will have fixed those scalability issues already :-)
HTH