Email Reader: Sure, Siri can compose emails for you, and even display your unread emails (or an email search). But try to get Siri to read you even just one offer from a hapless overseas banker looking to cash you in on an inheritance, and you'll be in for disappointment. Given that Siri can already read text messages, it seems like it wouldn't be a big leap to add emails. Understandably, if someone's sent you a ten-page email, or one that's heavily formatted in HTML, speech might not be ideal medium for consuming a message, but perhaps over a certain length, Siri could give you the option to just hear a preview. And who knows, maybe some day Siri will be smart enough to just summarize the salient details. It'd also be nice if Siri could be instructed to flag emails and to display your flagged messages.
Read It All: Speaking of reading your own data aloud to you, it'd be great if Siri could read details from other stock Apple apps, like Notes and appointments in Calendar, when you asked it do so. Siri says "I can't read your notes to you." Can't, Siri? Or won't?
Better Reminders: Reminding yourself to do things using Siri is quick and easy—but it could be easier. For one thing, you can't use Siri to change reminders once you've created them, nor can you mark them as complete. And if you want to add milk, orange juice, and bananas to your shopping list, you have to do so separately, confirming each one in turn. But Siri has shown itself able to distinguish multiple items in the case of recipients for text messages and emails, so why not here too? It would be far easier to say "Add milk and bananas and orange juice to my shopping list." Well, at least for the human doing the asking.
Launching Apps: It's easy to launch the apps in your iPhone's dock or on your main home screen. Once you load up more than a screenful or two of apps, however, finding the right one becomes a bit of a slog—even if you rely on Spotlight, it still means tapping out the first few characters of the name of the app you're after. Right now, if you instruct Siri to "Launch Photos," it responds: "I'd like to, but I'm not allowed to." If Siri's overlords in Cupertino could instead grant that permission, launching tucked-away apps would quickly become as easy as saying "1, 2, 3." Though we're not sure what app that would launch.