1. custom ringtones...many don't care about this, but I like it. Stock ringtones are horrible. This is coming later this year for 3rd party apps, but unless they allow ME to sync my own ringtones without using some crap 'bestringt0nez' app, and what THEY have available, I will still unlock for this reason alone.
2. custom colors. I like the stock green, but thats it. The rest look bad on the Super AMOLED the Focus has. Blue is ok I guess. Hopefully MS allows something like the current Advanced Config tool I use. Color wheel, hex #'s ect in an advanced color settings. I doubt they will keep the same 8 colors forever, so I'm hopeful.
3. Home brewed apps, beta apps ect. When MS releases the new marketplace to allow private apps, beta apps ect, and the Rating ability (pg, mature ect) so dev's can put in more adult/violent content without being rejected from the market, this won't be much of an issue.
I never use it to steal apps, and hope those that do are few.