Moved into a new place and DLS line is in the kitchen so I now have to hook up my wireless N router to modem in kitchen. I used to hook up my PS3, TV, and Blu Ray directly to router because I figured it would be faster for streaming music and video; now that the connection is all wireless about 100 ft away will I lose connection strength.
Wired still beats wireless these days no matter how much better the wireless companies are advertising. So, yep, your video streaming will definately suffer like in Netflix streaming, you'll probably get occasional stuttering or the quality might downgrade every now and then. If you're just surfing the net without streaming though, you'll be fine.
I agree with filhart - indoors it should not be too far than 50ft. For your DSL line you can try hooking up another switch hub with a category 5e UTP (wire solutions) or you can try bridging two routers together (wireless).