200 MB has NEVER been "normal". There really is no Normal. A new phone that has never been used will have about 300 MB of "other". As soon as you start using the built-in apps Other will go up, because all of your data for built in apps is part of Other. Here's what is in Other:
- email messages and attachments
- Calendar entries
- Text messages
- MMS messages and attachments
- Genius data
- Music cover art
- Operating system settings
- Settings for all of your apps, such as email servers, user ids, passwords, etc.
- Safari cache
- Game Center status
- Music catalog
Probably a few I've missed.
You will find posts from people who said they recovered over 3 GB of space by just deleting old text messages.
If you want Other to be smaller you will have to keep less data on your phone; delete old MMS and texts, delete old email (especially from the "deleted" folder), clear the cache, eliminate cover art.
Sometimes "Other" includes data corruption. If you suspect this is a possibility try connecting to iTunes and click the Restore iPhone button. First restore from backup; the Other doesn't get any smaller you can Restore again and set up as New, then add your content back separately from your backup.