It'd be really awesome if they could develop a search engine or phone (I know they tried) that had an open standards / web-compatible development kit.
I want an anti-Google / anti-Apple. Something we own and can extend. Something that doesn't sell our data.
I'd also like to see Mozilla doing lobbying. Partnering with the EFF. We've strayed so far from the bright and open Internet of the 90's and 00's. It's depressing to think about how locked up and proprietary it's all become.
I'll buy Mozilla / Firefox merch. I'll pay a subscription.
edit: Talk to Shuttleworth. Fold Ubuntu in. I'll buy a Mozilla phone and a Mozilla laptop.