Now I am really confused and a bit upset too. The agencies never made any mention of the shortage list or anything else. They are also still placing candidates from their pool on their website in positions in the UK. So, I guess now I will have a talk with them and see what is really going on.
If I understand it right, you need 50 points to qualify for the Tier 2 visa. If your job is listed on the shortages list, then you can automatically get the 50 points. However, as loveaturtle mentioned, English/Drama teachers are not on the shortages list, only Science and Maths teachers are. So you cannot get a Tier 2 visa that way.
Your other option is to get 50 points from your qualifications, expected earnings and company sponsorship. You will get 10 points for your degrees, either 0 or 5 points for expected earnings (if you are not likely to be able to earn more than £19,999) and then 30 points for company sponsorship... which is still only 45 points, even if you manage to find a job.
Unfortunately though, it is probably going to be almost impossible to get company sponsorship, because there are hundreds, maybe thousands, of newly qualified English and/or Theatre teachers graduating every summer, already in the UK and looking for these jobs ... and due to the recession, not even British teachers (non-Science/Maths subjects) are able to get jobs that easily (one of my friends (who is British) is a newly qualified primary school teacher and applied for 60 teaching jobs last year before being offered one). Plus, even if a school can't find a suitable teacher from within the UK, they then have to prove that they couldn't find anyone in the other 26 EU countries either before they can hire you (and there are a lot of people in the EU - 500 million).