Of course, it all comes down to clamping down the security of your WP installation.
+1 for that and good job locking down your install. It takes effort but is definitely worth it.
*If WP 3.2.1 itself was vulnerable, you would see a lot more hacked sites.
Amen to that!
Guys? WordPress is not your web server or hosting provider. It's just another software package that you are running.
It's not easy to keep it all up to date, but reflexively blaming WordPress will a) not solve your problem and b) waste your time when you keep getting hacked.
If you run or are using an insecure web server, if you don't keep up your versions of your web server software, your PHP, your support libraries, your Linux distro, etc. then you will get hacked. It's too easy for bots to find vulnerable installations; they're not targeting YOU, they are looking for low hanging fruit.
There is hope and if you've the patience and are willing to learn new things then give these a read.
Safety net: I tell you three times, backup, backup, backup. And learn how to restore. Practice restoring, with a good file and database backup you'll have the best way to fix things. Automated backups are your friend and I keep mine off the web server every night.
Harden your installation. Your web server runs as a userid and there is not really a good reason to let all userids on your server be able to write to the WordPress directories. You can really lock down the file system but some nice features such as auto update will not work. You'll have to update your themes, plugins, and WordPress files by hand if you tighten the permissions too much. If you keep getting hacked, then that maybe the way to go.
These are good starts. With a little system administration experience under your belt, you'll enjoy having a good WordPress install.