Please develop an app that is compatible with Roku, etc. We use Dropbox for our family memories, and it would be amazing to just log into our DropBox app on the tv to watch home videos.
That's not really a platform that Dropbox would develop for. Their core business is file synchronization and collaboration. They rarely develop specialized apps, and the few that they've created (or acquired) are often discontinued in short order.
Your best option is to use one of the third-party apps that can connect to your Dropbox account, such as Roksbox.
Just want to quickly flag that you can also use Plex or Roksbox to access your Dropbox files on Roku.
With Roksbox, once installed, you'll go to setup and select "add media source" and select Dropbox. You'll then be directed to log into your Dropbox account from the app. Once you authorize Roksbox in your Dropbox account, you'll be able to access your files on your TV.