The patch that presumably will solve MLB 2K10's connectivity problems in online multiplayer has been finished and submitted for certification on the Xbox 360, meaning the fix should be arriving shortly.
There are no details on what the patch will entail but a multiplayer fix has got to be among them. I can suggest a ton of AI fixes, especially in My Player regarding when your manager lifts you if you're a pitcher. Pasta Padre notes the fielder arm strength maybe should be backed down and I concur. I've seen - and benefited from - a lot of bullet throws from a shortstop ranging into shallow left field.
No word on a patch yet for the PS3. I don't know if its players have seen the same troubles with ranked matches - this workaround (not really a workaround, just something that keeps you from being frozen in the matchup screen) published by 2K Sports describes Xbox 360 controls. 2K Sports knows its greatest constituency is on the 360 and will take care of that first, but it'd be poor form to publish no gameplay-refining patch at all for the PS3 base.
MLB 2K10 Patch Completed For 360 [Pasta Padre]