I went "paperless" taking two graduate mechanical engineering classes this semester, using Note Taker HD on the iPad. It takes some getting used to, but once you figure out the workflow issues (Good Reader and Drop Box are a must), it is incredibly convenient. I evaluated 8 or 9 different iPad note taker apps, and at the time (August 2011), the only one that could do everything I wanted (easy PDF import for annotations, zoom feature, ability to draw shapes, easy export) was Note Taker HD. You will also NEED a stylus. Controlling a tablet UI is fine with your fingers - writing text and drawing diagrams for an hour during a class with your fingers just doesn't cut it. I love my Wacom stylus for iPad, though I have actually worn through it in just 3 months. You will probably need to try several (I tried 3 different ones) before you find the one that is right for you.

The issue is not just if it is good for reading PDFs - you also need to be able to organize the papers, create citations, make notes (and organize them), and most importantly, actually get the PDFs of the academic papers to begin with. The difficulty of this last one varies by field - some fields (e.g., mathematics) have a more-or-less central place to get stuff (if you are affiliated with a university with subscription access). Others require you to get papers from multiple different online sources, which can be a huge pain. I spent a lot of time on this and the only good solution I've found is the Papers application on the Mac + the purpose-built Papers Touch reader application on the iPad. This combination addresses all of those needs in a way that is tailored specifically for someone doing research who needs to review current scientific papers. In addition to being a graduate student myself, I'm the computer support guy in one of the largest departments at a major research university. For some of my users the functionality in this combination is enough to justify the purchase of a Mac laptop + iPad just for this purpose. While not perfect (having to have a Mac makes it a lot less than perfect if you don't use a Mac already, or don't have budget from your institution to support a purchase), it is the best end-to-end solution out there that I've found.

Wireless will NEVER replace wired networks completely. Because wireless is a shared medium (think "hub"), there is finite bandwidth available within a given volume of space (defined by signal strength and other factors). If you have a combination of node density and bandwidth needs that exceed what wireless can provide, you have to go with wired networks. Wired networks go over a non-shared medium (think "switch"), so you can scale the bandwidth in high-density environments. Do I think wired networks will become less and less the norm? Yes. Do I think wired networks will go away completely? No way in hell.