So I have a 2011 MBP on Lion that isn't seeing this issue, but a 2010 Macbook on Lion that is seeing the issue of no HTTP traffic after waking, ping and UDP traffic work.
WiFi is fine on iPad, iPhones, iPods, and AppleTV..... Wow, I own too many apple products...
I found a solution for my Macbook, hope this helps someone else, but before I give the solution, I'll list everything I tried.
1. Rebooted Macbook
2. Rebooted Time Capsule
3. Rebooted Airport Express
4. Removed all previous WiFi network settings.
5. Disabled Passive FTP Mode
6. Rebooted Macbook again
7. Added static DNS entry in network settings
8. Turned of 802.11n on Time Capsule
9. Rebooted Time Capsule
10. Tweaked Network Settings in Chrome and Safari
11. Completely removed cache in Chrome and Safari
12. Rebooted Macbook
13. Bought a Netgear router
14. Set Netgear to 802.11b
15. Rebooted Netgear router
16. Rebooted Macbook
17. Almost threw the Macbook in the oven.. 🙂
So my solution.....
Took CD out of slot and wifi started working after waking from sleep. Everytime I opened the lid, the CD slot would go crazy, so I figured that since my MBP didn't have a CD in the slot I should take it out of the Macbook, and now HTTP traffic passes every time it wakes. Weird, but it works.
I love Lion for the speed, but the WiFi issue has really tarnished that "it just works" reputation Apple is known for.