It there just not in testing. It is likely not to be released with Squeeze (see Debian bugs #527840,#528807, #524679).
http://packages.debian.org/search?ke...ll§ion=all
Package xpdf
* etch (oldstable) (text): Portable Document Format (PDF) suite
3.01-9.1+etch6: all
* etch-m68k (text): Portable Document Format (PDF) suite
3.01-9: all
* etch-backports (text): Portable Document Format (PDF) suite
3.02-1.4~bpo40+1 [backports]: all
* lenny (stable) (text): Portable Document Format (PDF) suite
3.02-1.4+lenny2 [security]: all
* sid (unstable) (text): Portable Document Format (PDF) suite
3.02-2: all