Because liens defeat subsequent security interests in property, you likely will no longer have the ability to use your property as collateral against any loans while the lien is in effect. This could present problems with your ability to secure new mortgages or car loans, for example.
Additionally, a tax lien could negatively affect your credit rating, making it much more difficult to obtain a lease, for example.
Most importantly, although the lien itself does not effect a transfer of the property to the government, the government may accomplish transfer of ownership either through a judicial foreclosure of the lien, or through a levy.