The display on the Galaxy 2 / Infuse / Charge all use SAMOLED-plus screens, which is different than the original SAMOLED screens seen on all of Sammy's older OLED handsets.
Likely Samsung's fault for not marketing the newer screens properly, or making it clear why text looked like **** on their older screens, there's a good deal of misinformation over the clarity of OLED vs the iPhone 4's high res display.
SAMOLED uses a pentile matrix LED. Google "Nexus One Pentile" for an in depth explanation as to why this sucks, but ultimately there are fewer subpixels (8 to each pixel), and more green than blue or red subpixels, causing the actual resolution of the Nexus one / Original Galaxy to be 653x392 rather than 800x480 as advertised. LCD's can use a Pentile matrix as well, the Atrix 4g uses a pentile screen. It's effective resolution is much lower than the stated 960x540
The way the pentile formation attempts to process diagonal lines causes it to be even worse than it's effective resolution at displaying high contrast images like text (it uses a dithering effect, and a number of filters to display lines), and better at video. Words tend to look jagged and blurry. I found text to be worse on the Nexus than my 480x320 3GS.
SAMOLED-Plus uses a conventional stripe matrix and looks as good as any 800x480 LCD (Droid, Evo, etc), perhaps even better since OLED is such a sexy beast on its own.
While the Galaxy 2/ Infuse still fall short of the iPhone 4's high res display, they should still look sharp, and will be excellent for text. Around 50% sharper than the display on the Galaxy 1.