Serve same bundle with different conditions

I've been trying to come up with a simple way to get around the data URI issue in IE 7. I noticed that DocumentCloud/Jammit ignores the MHTML thing altogether and just serves IE 7 the same CSS without the data URI, (from www.documentcloud.org/public/search/):

```

```

Note the wonky opening comment, ``.

Suppose Cassette could do something like:

```
bundles.Add(
"styles/bundles/ui",
b => b.Processor = new StylesheetPipeline()
.Condition("if lte IE 7")
);
bundles.Add(
"styles/bundles/ui",
b => b.Processor = new StylesheetPipeline()
.Condition("(!IE)|(gte IE 8)")
.EmbedImages(p => p.Contains("/embed/"))
);
```

What do you think?

Currently, this throws an error, `A StylesheetBundle with the path "~/styles/bundles/ui" has already been added to the collection.`. Also, there would need to be a way to specify that special comment syntax.