Hi all,
ByteBandit, the Celestial Heavens forums moderator, decided to upload some (a few hundreds, as he said) HoMM2 maps. Some of them are maps from the Astral Wizard site, which sadly went down some time ago.
He created a Yahoo! group, from which you can download those maps (after you register on Yahoo!, if you aren't already, and join the group). There you can also find links to his HoMM3 (and WoG) map archives, but again on Yahoo!
HoMM2 maps are being uploaded now, atm there is 126 maps. So if you feel need to play new maps, join the group and download them all, if you wish. I plan to download them all and upload them on rapidshare.com for better availability.
Maps from his HoMM3 archives are probably from Celestial Heavens.
(or from MapHaven, but the site doesn't work now)

The Astral Wizard, Phil McCrum, uploaded all the maps that used to be on his AstralWizard.com web-site, to his Skydrive. Copy the following link (as one line without spaces) into your preferred browser:
http://cid-0fac24965c71c1b1.skydrive.live.com/browse.aspx/Heroes%20of%20Migh
t%20and%20Magic%20Archives
The archives include HOMM1, HOMM2 and HOMM3 maps. =)
Enjoy!
Best regards,
Steven.

I looked at that site. I can tell you that's not all of them. I have 700 maps up on the HoMM2 Map Archives now, and 90 per cent of them are from AW. Total amount of storage space used on the Archives is 78 MB. The ones offered on the site you gave are not all there.

Sorry about that. =) Phil McCrum the AW gave that link. I guess there could have been a space restriction on the Skydrive, or maybe some other reason.
Anyway, it's good that you have all the maps up at the HOMM2 Map Archives Yahoo Group! =)
Best regards,
Steven.