Hi Resolution download - question on authencity of the files


Hello all,
I have never downloaded a hi-rez album till date.
I recently heard samples of Norah Jones Day Breaks album and was thinking of purchasing the hi-rez album via acousticsounds.com or hdtracks.com or prostudiomasters.com. Question is - are these REAL hi-rez files or are these just up-sampled CD version? Sorry if this is a dumb question, but I am currently listening to "Celtic Woman - A New Journey" and the recording on this CD is superb. I wondered how much the "quality" of such a nicely recorded album can be improved. Hence the question. I am not sure if the FLAC 96kHz/24bit version is a real one that I would be able to distinguish from a CD 16/44 version.
Thanks in advance for your thoughts.
128x128milpai
I've found that you have to be careful. Redbook--standard CD quality--can be excellent. Hi-Rez sometimes is no better. I wish you could easily see how the hi-Rez was created. From original analog tape digitized at a high-sampling rate and/or remastered? That would be nice to know. 
I checked BlueNote site and Norah Jones site. Nothing about downloads is mentioned there.
I have not delved into digital downloads for the simple reason there is no software to keep my classical music files in order. Renaming Beethoven symphonies as #5, 5, No5, No.5, etc is too much for me!!! It does not help that decent CD beats SACD or hi-rez downloads on my stereo. LPs sound sooo much better to my ears that $25 for the download vs. $30 for LP is a no-brainer for me. All system-dependent of course, thats why I (finally!) posted photos of my big rig today here at a-gon. For those who have $100k dCS stack the results may differ from mine...

I have purchased about 15 high res from hdtraks. I frankly do not like any of them and a few compare unfavorably to my ripped files from cd - for example, two rem albums. it could be me or my system but thats my experience.