As the end of 2011 approaches, a slate of business tax breaks are scheduled to expire. Their demise - or renewal - may ease your year-end tax planning.

In what has become an annual ritual, here is a look at the most popular expiring small and medium-sized business tax breaks, accompanied by fearless predictions about which ones will be extended.

100% First-Year Bonus Depreciation

For calendar year 2011, business taxpayers can write off the entire cost of qualifying new (not used) assets--including most software, vehicles, and equipment in general. Assets must be placed in service -- hooked up and ready for business use -- by 12/31/11 to be eligible.

Prediction: More likely than not to be extended through 2012 thanks to the weak economy. Will that happen before the end of this year? One can only hope.

Liberalized Section 179 Deductions

For tax years beginning in 2011, eligible small and medium-sized businesses can immediately write off up to $500,000 of qualifying new and used assets--including most software, certain "heavy" vehicles, most equipment, and up to $250,000 of qualifying real estate improvements. Assets must be placed in service (hooked up and ready for business use) by the end of the tax year to be eligible. For tax years beginning in 2012, the maximum Section 179 deduction is scheduled to fall to only $134,000, and deductions for real estate improvements are scheduled to go away.

Prediction: More likely than not to be extended through 2012, thanks to the weak economy.

0% Tax Rate on Future Gains from Qualified Small Business Stock

For qualified small business corporation (QSBC) stock that is issued in calendar year 2011, a 100% federal gain exclusion break is potentially available. That equates to a 0% federal income tax rate on future profits from selling QSBC shares down the road. You must hold the shares for more than five years to be eligible, and many companies will fail to meet the definition of a QSBC. However, the 0% rate is obviously a great deal for eligible shareholders. For QSBC shares issued in 2012, the gain exclusion percentage is scheduled to drop to 50%.

Prediction: 50/50 chance that the 100% gain exclusion will be extended through 2012, thanks to the weak economy.

Read on for more on business tax breaks.