When next gen consoles offer inbuilt tools to record and share game play videos, Nintendo is left in the dust looking like a old relic from the past. Looking how the sales of the Wii-U are going, it seems pretty stupid to turn down the free marketing from the internet videos.
You're using two lenses I'd be keen on buying! I'm already convinced I want the 100mm f2.8L, but how are you finding the Sigma 50mm f1.4? I don't want to exclusively buy Canon lenses, so I was looking at a Sigma 50mm or possibly a Carl Zeiss 50mm, just to expand my experiences with different lenses.
I can really recommend the Sigma 50mm 1.4. It is the lens that I use 85% of the time. It might not be the sharpest and sometimes (1 in every 100 shots) it might miss the focus. That said the way it captures light is unlike with any other lens. It works really well in low light (because it is optimized for this) but is nothing special when it is bright outside (sunny 16-ish). I live in Finland and here that is not a problem since dark, cold seasons are long and indoor areas are more dimly lit than in other places. Works great with flashes, specially if you are using color gels. So if you want shoot mainly below 2.8 and you are not taking photos in bright outdoors, get it.
100mm 2.8L USM IS is nice lens and there is a reason why it is one of the best selling Canon lenses. Word of warning though, for me, 100mm was surprisingly hard to get used to after using only lenses in 50 -17mm category. It took quite a while before I could make good enough compositions with it regularly.