This wasn’t even a challenge for me. Can some people really not read this?
I’m not trying to snark on those who can’t (Personally, I don’t believe one’s inability to read it has anything to do with one’s intelligence.), I just think it’s interesting how the brain works.
17 l00k5 l1k3 l3375p34k.
f y cn rd ths, itn tyg h myxbl cd.
Uh… huh?
But, yeah, I could “read” the linked “text” (so to speak) just fine. Ugly as hell, and it hurts the brain in weird kinds of ways. But it was easier to wade through than Finnegan’s Wake!
Meihem In Ce Klasrum did it beter.
I don’t think the question is whether you can read it–the question is whether you’ve got a good immune system against mind-viruses. This one chooses a classic vector. It gives a trivially-easy puzzle, suggests it’s much harder than it is, compliments your intelligence, and then asks for you to forward it to other people. As long as folks think it shows their intelligence to forward it, they’ll do so, propagating the mind-virus.
All that said, yeah, it’s interesting that folks can read it, in the sense that it mixes a traditional font with a nontraditional font, and we can decipher nontraditional fonts pretty easily. The similar messages that mix up letters and are still readable are, I think, even more interesting: msesgaes lkie tihs, for eaxplme, weehr bgeninng and ednnig ltetres saty the smae, but mdilde ltetres are srcmalebd. They take a little more work to read but are way more legible than I’d think they’d be.
“W17H 0U7” should be one word, not two.
Why doesn’t the 7 have the cross-hatch in it? It’s easy once you see it that way.
The stuff in the link provided by the OP is not really clever nor does it show any particular thing about reading or processing written English. That’s because the substitutions are carefully selected.
Great. And it took me about a minute to figure “53RV35” out from context…
It’s a spoof of an old advertising campaign for secretarial school: “f y cn rd ths, y cn gt a gd jb.”
Yep… What prize do I get??
I can also read LOLspeak… oddly enough I can not write it…strange,that.
No sweat. Took me maybe 10 % longer than plain English.
Once my eyes hit the third line, I could go back and read it from the beginning nearly as fast as I could English. But I have the advantage of having been drinking.
I read it fine from the get-go, but I have the advantage of being a huge nerd. 
The puzzle is trivially easy because of the way most (not all) literate humans read English text, the relevant part is whether the reader is enough of a rube to be so proud of their awesomeness they were gulled into forwarding the message.
I got hung up on the first word of the second line then breezed thru the rest no problem. Still not sure what it’s supposed to be.
To me, it reads “Server not found.” 
“I cdn’uolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg: the phaonmneel pweor of the hmuan mnid. Aoccdrnig to a rseearch taem at Cmabrigde Uinervtisy, it deosn’t mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.”
f y cn rd ths, y mght lk t lrn hbrw r rbc. Y’d b ntrl.
