OK Google, remind me to write that article about how truly useful you're becoming.
At long last, some back-end server changes have fixed a couple of annoyances in Android's voice agent. First, asking Google Now to set a timer actually sets a timer. Shocking, I know, but it used to actually set an alarm for a future time. We wrote about the possibility of this feature coming last month. The final interface is different than the mockup seen in that article, but the feature is enabled.
Also new is the ability to set reminders entirely by voice. Of course, you've been able to set reminders for some time now. But it wasn't entirely hands-off—after speaking a phrase to set a reminder, you would need to tap the resulting confirmation to set it. Now, Google Now will ask "do you want to set this reminder?" to which you can reply "Yes" or "No", and adjust the settings by hand if you like.
You don't need to wait for an app update to make use of these features. They're enabled on the server side, so Google Now should operate this way for you immediately.