Strange. When I try using linktoapp.com in Mobile Safari on my OS 2.1 iPod Touch it doesn't work - same error as just entering the direct App Store link. But on my OS 2.2 iPhone it works.
The straight up links copied from the app store don't work, but links on touch arcade, and links from linktoapp.com work.
Links in the Apple's own RSS feeds, which are heavily syndicated inc. iTunes App Store RSS Feeds use the new "itunes" link, as do ALL of the affiliate links generated by linkshare.com
Yes, the old 'phobos' links on my webapp version at Daily iPhone Apps Chart work, But it's a real pain in the **** to maintain and despite a couple of thousand users per day, it simply doesn't pay off as I can no longer use the affiliate links for the whopping 5% commission