Don't know what to blame it for - on G1 hardware, or on Android software, but the voice dialer on G1 deeply and profoundly sucks.
Out of existing address book, it can recognize 1 (one) name.
It would've been tolerable if it could recognize digits, but no, it can't recognize them either. Repeatedly.
I would've blamed that on the fact that I speak with an accent, if not for the fact that a stone age old PEBL had just slight problems with it, and BlackBerry Curve didn't have any at all.
I wonder if voice recognition actually runs locally on the phone, or remotely with your voice input channeled to a Google server - just like Picasa 3 does with face recognition. Also wonder if the algorithm is fixed, or self-learning - it gives me way too may choices when it fails.
Verdict: unusable in current state. If you're using voice dialing a lot, make sure it works for you before you buy the phone.
Update: I'm not the one whose voice it doesn't recognize. Native speakers have just as much luck as I do.
Update: RC29 didn't help much.