There's a database, BP, and they do mention on the Brennan site, that you can plug in a keyboard (the one they link to is a miniature one, presumably chosen to be small, but a 5 quid PS/2 style seems all that is needed, so even if the installed database isn't aware of the latest CDs the labour of adding tracks after that shouldn't be too onerous.
The downloadable PDF user guide (or the website itself) goes into some detail about lossless, and various levels of compression (320k, 192k, and 128k are other options, and they show the numbers of albums expected to be stored).
Thanks for the info on lossless. I have not been an audio "buff" so can happily cope with 192 kbps and not find fault with the audio, though know that DAB falls down for those who do have sensitive ears!
I mentioned the Sonos as that integrates with existing media storage, creates its own wi-fi net, and Sonos r/c costs near 300 quid but there's an iPhone application to control the Sonos kit available free or for a few quid. They also provide Mac and Windows control software to link with the Sonos, but I've only seen the boxes and don't have that at home (yet).
Seems to me the Brennan is a rather neat unit, but get in fast if that's what you want as the queue for new units seems to be growing, so leave it too long and you won't get one before Christmas...
I'd have gone for the 80 GB unit except that on further reading I couldn't easily find "albums" of music off the 100+ GB I already have, if they are kept on an external drive (drat, was thinking about copying them onto a 320 GB drive, to allow for more to be stored in one drive). So I'd have to dig out the originals (and not all are in my possession nowadays, as I lent an Australian girl all my classical CDs and she skipped off with them!)