Samsung has a reputation for not being the greatest at updating their devices, but this week has been especially rough for them. First, Microsoft had to halt an update to the Samsung Omnia 7 due to reports of bricked devices. Today, Sprint has just stopped pushing the Android 2.2 update for the Epic as users have found hardware problems after applying it.
According to Sprint's support forum, there have been an increased number of calls into their Care Centre about issues with wireless data connectivity and the ability to access the SD card. While it's a relief that no one has reported a bricked phone, I can imagine the long wait for Froyo would be made that much worse by having it break some core functionalities of your device.
If you are one of the unlucky ones who are affected by these issues, Sprint is saying that a hard reset should solve your troubles. If you are among those who updated without these issues before it was pulled, have fun with all that new(ish) hotness.