Here's what I committed for conditional tracepoints.  On to the next piece!

Stan

2009-07-14  Stan Shebs  <stan@codesourcery.com>

    Conditional tracepoints.
    * ax-gdb.h (gen_eval_for_expr): Declare.
    * ax-gdb.c (gen_expr): Generate bytecodes for BINOP_EQUAL
    and other comparisons.
    (gen_eval_for_expr): New function.
    (agent_eval_command): New maintenance command.
    (_initialize_ax_gdb): Define the command.
    * remote.c (struct remote_state): New field cond_tracepoints.
    (PACKET_ConditionalTracepoints): New packet config type.
    (remote_cond_tracepoint_feature): New function.
    (remote_protocol_features): Add ConditionalTracepoints.
    (remote_supports_cond_tracepoints): New function.
    (_initialize_remote): Add ConditionalTracepoints.
    * tracepoint.c (download_tracepoint): Add conditional.
    * NEWS: Mention conditional tracepoints.

    * gdb.texinfo (Tracepoint Conditions): New section.
    (General Query Packets): Describe ConditionalTracepoints.
    (Tracepoint Packets): Describe condition field.
    (Maintenance Commands): Describe maint agent-eval.
    * agentexpr.texi (Using Agent Expressions): Mention eval usage.

    * gdb.trace/tracecmd.exp: Add basic test of tracepoint conditions.