Usually with Sony's PSP updates the new features added are a fairly poor attempt to cover up exploit fixes, 90 per cent of which amount to stopping homebrew applications from running. Not with 3.8 though, oh no, because Sony is adding a whole host of new and useful features, if its Japanese website is to be believed.
First of these is unlikely to matter to almost everyone reading this, but is interesting nonetheless. If you are lucky enough to have a new Slim and Lite PSP and a 1-Seg tuner (as yet unusable outside the Far East) you'll see some funky new recording and EPG features available for use; the former meaning that 1-Seg broadcasts can now be saved to the PSP memory card and the latter going so far as to offer the ability to have the PSP turn on, record a program and turn off again according to a user-defined schedule - nifty!
More appealing for us Western types is the addition of streaming radio, from Shoutcast and again, these streams can be recorded to memory stick, to the delight of copyright holders the world over no doubt. RSS feed support is also getting a boost to allow OPML (RSS feeds aggregation) and image display while browsing RSS. Japan will be seeing the update come the 18th, and rumour on the PlayStation forums has it that the rest of the world wont be waiting too long after.