Sorry, we are not supporting to zoom in in form design view. But for form filling page, you can zoom in directly using the browser. If you like, you may submit a feature request and vote it in http://forums.adobe.com/community/formscentral?view=idea.
Actually there's a workaround for now if you really need to zoom. You may use the Magnifier of Windows. You can find it from Start->Accessories->Ease of Access->Magnifier. It's just a temporary solution. Please let me know if you have any more questions. Thanks!
This is really bad. There is no way to zoom in without changing the browser zoom ?
Sorry you can't zoom in the Design Tab but you can zoom the View Responses. The zoom control is in the bottom right corner.