If you only have a few buttons, lawndartcatcher's answer is your best bet. If "bulk load" means >10 or so, then here's one alternative. It's more sophisticated, and it does save in a batch, but I wouldn't swear it's significantly quicker.
Create your text layers over the background. Each bit of text will be on its own layer, and if you have Effects applied, you can replicate the effects by just copying the first text layer and changing the text.
Now turn on your text layers one at a time and create a Layer Comp (
Window > Layer Comps) for each one. Be sure that "Visibility" is checked. (Do this after you create the text layers, to avoid Photoshop nagging you about the comps being out of date.)
- When you're done, you'll have a set of Layer Comps that include the background and one text layer each.
File > Scripts > Layer Comps to Files and pick your file options in the dialog.
You'll have a set of individual numbered files that you can use as-is or rename as needed.
Hope that helps.