Too many
40ish
I'm trying the approach started in Cpjr's thread and expanded by Jazjon. So far so good. In a nutshell:
1. Complete the pwn process without restoring any data or apps first. Just treat as new phone.
2. Install the core Cydia/Installer apps you need, etc etc. Take special care that you leave time between operations before installing apps. Cydia doesn't seem to know/care if the phone is busy with other operations and will do it's thing, which can resort in a couple hours worth or restoring
3. Begin the process of installing your apps by downloading from the iPhone Appstore application. Again, leave time in between, don't rush it.
If you do anything that will need a reset of the phone, like changing a Winterboard theme (maybe not reset but you get the idea) and such, again be sure you begin the process only if the phone is not busy with another task, like installing an app.
Looks like we just need to baby these things until the phone, apps and jailbreak installers are out of the teething stages.