I woke up this morning to several reports from people saying they had gotten an OTA for their Sidekick LX 2009. It’s looking like this update is a combination of the bug fix OTA I mentioned awhile back and the new Mobile Backup support. You should hopefully see less crashes in your Sidekick LX 2009 once this update is applied. The OTA may cause your device to hard reset. Don’t freak out though, all your data should be backed up to Danger’s servers, so it’ll come back. And once you have Mobile Backup, your address book will be backed up to T-Mobile’s servers as well! Hooray for backup!
For those hardcore geeks, the new OS version is 5.0/270115. A couple more screenshots: