I'm hoping this feature is buried somewhere and I'm just too dense to find it. I have a T-mo Dash w/ WM 6. Though my phone will have an audible alarm and persistent icon when I get voicemail, I often miss it, or forget to check if i'm tied up at the moment I get it. It's not hours or the next day that I realize I haven't checke voicemail. My old phone would let me set a reminder every 10 minutes (or whatever frequency I select) that I need to check voicemail. Support says it doesn't exist. Is this correct, and if so, how can I champion this to get added in a future update?
For ultimate control, I suggest phoneAlarm. If that's more than you want or need, there is a setting in WM5 for repeating alerts. Is it gone in WM6? Start, Settings, Unread Message Alert. Make sure it's on.
Off topic: I just noticed your sig--your last three devices, Samsung i600, Samsung i730, Motorola Q. Same as mine. i730 was awesome, but a brick to carry and I never could get used to that slider.