Buzz has been flying for a while now around the hard drive's belated evolution into flash-based drives, much like the solid-state memory found in the iPod nano. Engadget has of course been covering this NAND flash memory for some time, while manufacturers have been demoing real-world notebooks that use them as early as March 2006. The advantages of these drives are far better power usage (meaning: much longer battery lives), faster seek times (meaning: stuff works faster), vastly improved durability (no moving parts) and even some claim "instantaneous" OS booting.
This all gets interesting when considering Apple's position, as they have one of the largest reputations with NAND flash memory manufacturers among PC makers, due to the success of the iPod. Sure, Samsung has been showing off their own flash-based notebook prototypes, but that's because they're cheating - they're one of the largest manufacturers of NAND memory. Apple's close relationship with these manufacturers is leading many to speculate that they could be one of the first manufacturers with a flash-based notebook, even as early as 2007, especially since Samsung is already selling commercial models with at least 32GB NAND drives baked in.
This is, of course, speculation, and when speculation comes from the rumor gurus, you'd darn well better take it with at least one, if not two, grains of salt. Besides, back in March, a 32GB NAND flash drive cost $900 alone at $30/GB. With the way things move in this industry, prices should undoubtedly be at least a little better by now, but the question of when they become appealing enough for manufacturers like Apple to start including them as standard parts is anyone's guess. If anything, I'll bet that we'll start seeing rumors of NAND-based MacBooks at Macworld San Francisco 07 once the season kicks in. Stay tuned.