If you are using CAPS in your title tags, either to highlight keywords or perhaps to follow brand guidelines, you do not need to worry about incurring the wrath of Google for it. There is no penalty or ranking issues with the use of caps.
The question came up on Twitter. There are also plenty of webpages that rank very well that make use of capital letters for entire keywords. There are also many keywords that are used in full capitals to meet branding guidelines, such as BMW or LEGO.
That said, just because you can do something, doesn’t necessarily mean you should. Title tags entirely in capital letters can make it hard to read, and chances are good that Google could rewrite the title as well. But for highlighting a keyword or two, or a brand, it can be an effective way to draw attention to it.
But from an SEO and ranking penalty perspective, go ahead and use capital letters.