Blizzard has made very clear in the past, and once again on the forums here, that they have no plans or intention to raise the level cap in the Diablo 3 beta.
“Nah. Thirteen will still be the level cap in Beta Patch 10, and we’ve no plans at this time to raise the cap in future patches.
In the end, the beta is mainly intended to test server stability as well as hardware/software compatibility, and that kind of testing isn’t really dependent on having a plethora of game content available (beyond Act 1, at least).
We know many of you are eager to see more of Sanctuary, though, and we can’t wait to take you on that journey once the game launches. In the meantime, we really do appreciate your feedback on current systems, bugs, and the overall user experience more than you know, and definitely encourage you to keep playing (and posting!) so long as you’re having fun. (:”
Blizzard has a long history of spoiling content, from letting top tier guilds beat yet to be released bosses in World of Warcraft to sharing end-game cinematics before they can be seen in game. This is great news for players who want to experience the challenge of the game for the first time when they pickup their copy of Diablo 3. This is also good news for profiteers who hope to achieve a competitive advantage by racing to max level and selling everything they get once there. This will create more content and adventure for the casual player to explore after the game releases and make it easier for profiteers to stay focused.
Important: Many of the strategies and tips I share here were originally inspired by the people at the Diablo 3 Gold Secrets Forum. If you're serious about making the big bucks in Diablo 3, or just being the best players, you need to signup ASAP.