I currently study traditional characters (reading, writing, tone). I would also like to study simplified characters, but ONLY for reading, in order to gain literacy with simplified documents. How can I do this?

Hi Odysseus, because you asked, I've just now published a list: http://www.skritter.cn/vocab/list?list=302418553
It contains the differences between traditional characters and simplified characters. So you don't have to study another 2000 over characters, but only these 600 differences.
What you want is not very easy to achieve and needs some effort and diligence from your side:
1. Learning Mode
Set your account to "Both" (traditional and simplified) and chose all 4 learning options (writing, reading, tone, definition). In this mode you can review both at the same time, but you should not add new traditional words, because otherwise Skritter will also add the simplified variant to your learning list. So I recommend to set your account to manually add. If you add simplified, then all 4 learning modes are activated.
2. Add Simplified characters from the list
Set your account to Simplified and to Reading only. Now add from the list as many characters as you wish (the easiest is to add say 20 items via the iOS app). Then Skritter will only add the simplified characters and set them to reading only. Once all items are loaded, go back to your account setting and set it according to 1). Skritter will ask you whether this change should apply back to existing lists, just say no, leave them as they are. You will then review all your existing items plus the simplified in reading mode.
3. Adding traditional items
Set your account to Traditional and chose all 4 learning options, then add more items to your learning queue. Once added, go back into learning mode 1).
So it's a bit tricky, therefore, I have stopped for the time being learning the traditionals and only continue with simplified. I think the Skritter guys are very busy in the moment with the example sentences, so no time to find a better way.
Example sentences: when your account is set to Both, you can add example sentences and they are set by default to tradional, so no problem for you.

Is there a simplified to traditional variant of this list?

You can do both, actually I did simplified to traditional. Just set your account to traditional and import from the list.

Rock on and kudos!

I appreciate the effort. This sounds like a good work around for the time being, but I hope when the developers have time they will add a feature by which this can be more easily achieved. Learning reading/writing/tone for one set and reading only for the other seems like it would be a popular and utile approach.

Odysseus, if I remember correctly, list individual learning setting is in the pipeline, but don't know whether this is coming with the next release alreay.
BTW, after adding simplified characters, you can set your account to traditional and previously added simplified items. I didn't try this out, because I had problems with example sentences. It might work perfectly for you.

The per-list parts and styles controls are coming sometime this summer, yes.

Will you post a list of what new features you plan to have in the next version? (Maybe in a separate thread).
Obviously with the caveat that nothing is guaranteed.

The next version of the iOS app is mostly to get the example sentences in there. The version after that we're not sure--focusing on some web features, which don't have as much of a planned release schedule.

I'm in the same boat as Odysseus. I study all options for traditional, but have a need to recognize (but not write) simplified characters. My situation is though that I still have a lot of vocabulary to acquire no matter what style.

If I have my settings to "both", but then set it to "traditional" manually per session, is it true that I will see the new words in both styles (i.e. recognition) but will only be asked to write traditional? This is really what I am looking for.

Nope; when you changed a temporary study setting like that, you go into review only mode and no new words are added. (This happens to prevent the list getting out of sync with some words having some parts skipped when added to My Words.) You'd currently have to do something more like Roland is suggesting, except it's easier now for the parts: each list has its own parts setting.

We still don't have per-list style, though, so you'd change your non-temporary study settings for that bit when you wanted to add some words, and just go to the list you wanted both styles added from while you have both styles adding enabled.