Where is the backup software for the arc?

[#1]

It is available here for previous phone:

http://m.sonyericsson.com/backup

And it should be useful to upgrade using SEUS.

[Uliwooly]

for your SMS use

backup & restore SMS

https://market.android.com/details?id=com.riteshsahu.SMSBackupRestore&feature=search_result

and for your MMS use Save MMS

https://market.android.com/details?id=com.schwimmer.android.mmsextract&feature=search_result

[Dr_Chris]

http://www.fjsoft.at/en/highlight.php You can also use My Phone Explorer, which is especially good for backing up and restoring messages.