Hello: Did you receive an answer to this? I, too, want to print Labels, Name Badges, etc, via a mail merge, in iWork Pages. I understand how to accomplish the mail merge in pages, but I cannot find a template, etc to use for the labels or name badges. I have been using my iMac since March and really find it to be a huge improvement over a PC, but I am still struggling with certain aspects of formatting, etc. Thank you.
Printing name badges via mail merge is not possible in Pages '09 currently. You can't use Address Book, either, because there is no way to omit address information when printing labels in Address Book. However, here's a workaround that I came up with. It's not the best, and kinda sucks that there has to be a workaround in the first place, but this produces a suitable result, even if the process is a little bit of a stretch. I used this to print name badges. It might take more fidgeting to get labels to come out right, but once you get it set right, you can save it as a template under the File menu in Pages.
The short answer is to use a custom paper size in Pages so that each label comes up as ONE page, instead of giving you a standard size page with several labels with the same name on it. You dig? So you'll make a small paper size (the size of your name badge or label) and then print several of those pages on one sheet of paper by using some print settings. If you think you can figure it out from that short explanation, go get 'em tiger!! If you're still wondering "wha???" then here's a step-by-step below.
1) open Pages. Set your document paper size to whatever size you want your labels or name badges to be. [you may need to manually measure the label paper.] You can set the paper size under the File menu-->Page Setup.
I did it in page layout mode and set my page size to w=3.5 h=2 with 0 margin around the entire thing.
2) set up your label or name badge with the appropriate or desired merge fields. You can do this by using the Insert menu. Add your desired formatting like font style and graphic decorations.
I just used a single text box and inserted the First and Last name merge fields. Then I centered them vertically and horizontally so the name sat squarely in the middle of the layout.
3) Select the cards you want to merge in your Address Book and drag them to the merge fields in your document. Merge to new document. You can send to printer, but we're going to change a few print settings either way.
4) If you haven't already, go to File-->Print and the print dialog comes up. [make sure you are looking at the expanded print view. if you are wondering what this is, here it is: the first thing you'll read at the TOP of the print dialog box is "Printer:", then a drop-down menu to the right of that, and then a little blue box with a black triangle in it to the right of that. click on the triangle. if the print dialog gets smaller, click the triangle again]
After the "Copies:" and "Pages:" areas, there is a drop-down menu. Make sure that is set to "Layout." The first thing under that drop-down should be "Pages per Sheet:". You can experiment with this for yourself, but at the paper size I used, I found 9 to be a suitable amount of pages per sheet. [so basically what we're doing here is printing 9 pages at 3.5in x 2in on ONE sheet of paper.] Next you should see "Border." You can turn that on or off to your liking. I used "Double Thin Line."
5) View in Print Preview. That might be under the "PDF" button on the lower left corner of the print dialog box.
6) Once opened in Preview, you can see what it's going to look like when you print it out. This is really helpful, because when I
didn't do this and printed straight from Pages, it did not work the way I wanted it to. Go to File-->Print and pull up the expanded print dialog box.
7) You may have to mess with the scale options near the bottom. I changed it to "No automatic page scaling" but I didn't try the other options.
8) Print out your document!
9) [Optional] Go back to Pages and save as a template for later use. You can do this under the File menu. When you save it as a template, don't save the merged document with the several dozen names in it. Save the original document that you started with before merging. It should only be one page (one
little page). Once saved as a template, it will show up at the bottom of your Template Browser in Pages.
Now, of course, you would have made any tweaks back in Pages before printing it out and/or saving it. I hope that solves your problem.
I know it's pretty round-about, but isn't that the nature of work-arounds, anyway?

A better idea, though is hitting up the feedback page.
www.apple.com/feedback and telling them what feature you want to see in the next incarnation of iWork. That's what I did!! All the best.